json_view: keep accept()'s string check out of run()

Clang 23 made run() slower on files without escapes (mesh.pretty +15 %) when the check-only string path was a separate call target. Dispatch inside slow_string() instead, so the call in run() is the same as before, and skip the SIMD run scan between escapes that follow each other (twitterescaped 1.11 -> 0.82 against the previous commit). Signed-off-by: Niels Lohmann <mail@nlohmann.me>
tests: avoid astyle-mangled build<> call in json_view builder test
2026-10-31 13:00:39 +00:00 · 2026-10-31 11:14:52 +01:00 · 2026-10-31 11:14:51 +01:00 · 2026-10-31 11:14:50 +01:00 · 2026-10-30 22:34:32 +01:00 · 2026-10-30 22:18:14 +01:00
28 changed files with 1164 additions and 1675 deletions
@@ -13,9 +13,15 @@ function never throws an exception for invalid input, and the returned `#!cpp bo
 is returned.

 The result is the same as that of `BasicJsonType::accept()` by design; the difference is how the check is made. This
-function runs the document's index builder (and discards the index), while `BasicJsonType::accept()` runs the SAX
-parser with a handler that ignores every event. Use this one if you go on to parse the same input with
-[`parse()`](parse.md) anyway, so that both use the same code; either is fine for a plain yes/no answer.
+function runs the document's builder, which checks the text as [`parse()`](parse.md) does, while
+`BasicJsonType::accept()` runs the SAX parser with a handler that ignores every event. Use this one if you go on to
+parse the same input with [`parse()`](parse.md) anyway, so that both use the same code; either is fine for a plain
+yes/no answer.
+
+When both `ignore_comments` and `ignore_trailing_commas` are `#!cpp false` (the default), the builder writes no index.
+With either option set, it builds the index as [`parse()`](parse.md) does and discards it: the result is the same, only
+the time differs. (Neither option needs the index; the variant that skips it exists only for the default options to
+keep the code size down.)

 ## Template parameters

@@ -68,10 +68,9 @@ Strong guarantee: there are no changes to the view or the document it refers to.
    - Throws [`out_of_range.404`](../../home/exceptions.md#jsonexceptionout_of_range404) if `ptr` cannot be resolved
      because a reference token is used on a primitive value.

-As for `BasicJsonType`, with [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) these exceptions name the JSON
-Pointer path of the value within the document, and with
-[`JSON_DIAGNOSTIC_POSITIONS`](../macros/json_diagnostic_positions.md) its bytes in the source text (when
-[`materialize()`](materialize.md) sets them).
+None of these exceptions carry a [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) path: the view has no
+`BasicJsonType` value to point at, so the exception is created without one, even if `BasicJsonType` was built with
+`JSON_DIAGNOSTICS` enabled.

 ## Complexity

@@ -20,9 +20,9 @@ Strong guarantee: there are no changes to the view or the document it refers to.
 Throws [`invalid_iterator.214`](../../home/exceptions.md#jsonexceptioninvalid_iterator214) if the view is
 [null](is_null.md) or [discarded](is_discarded.md), or if it is an empty array or object.

-As for `BasicJsonType`, with [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) the exception names the JSON Pointer
-path of the value within the document, and with [`JSON_DIAGNOSTIC_POSITIONS`](../macros/json_diagnostic_positions.md)
-its bytes in the source text (when [`materialize()`](materialize.md) sets them).
+This exception does not carry a [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) path: the view has no
+`BasicJsonType` value to point at, so the exception is created without one, even if `BasicJsonType` was built with
+`JSON_DIAGNOSTICS` enabled.

 ## Complexity

@@ -20,9 +20,9 @@ Strong guarantee: there are no changes to the view or the document it refers to.
 Throws [`invalid_iterator.214`](../../home/exceptions.md#jsonexceptioninvalid_iterator214) if the view is
 [null](is_null.md) or [discarded](is_discarded.md), or if it is an empty array or object.

-As for `BasicJsonType`, with [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) the exception names the JSON Pointer
-path of the value within the document, and with [`JSON_DIAGNOSTIC_POSITIONS`](../macros/json_diagnostic_positions.md)
-its bytes in the source text (when [`materialize()`](materialize.md) sets them).
+This exception does not carry a [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) path: the view has no
+`BasicJsonType` value to point at, so the exception is created without one, even if `BasicJsonType` was built with
+`JSON_DIAGNOSTICS` enabled.

 ## Complexity

@@ -80,13 +80,14 @@ Strong guarantee: there are no changes to the view or the document it refers to.
 - For every other `T`: whatever [`materialize().get<T>()`](../basic_json/get.md) throws — typically `type_error.302`,
  or whatever a user-provided `from_json()` throws.

-The exceptions thrown directly by this function or by a `from_json()` that reads the view (the first four bullets
-above) carry the context of those of `BasicJsonType`: with [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) the
-JSON Pointer path of the value within the document, and with
-[`JSON_DIAGNOSTIC_POSITIONS`](../macros/json_diagnostic_positions.md) its bytes in the source text. An exception
-thrown while converting through `materialize()` (the last bullet) is thrown by the materialized `BasicJsonType` value
-instead: its path is relative to the root of the view's subtree, because `materialize()` builds only the subtree
-(with parent pointers), so it is empty if the failing value is the subtree's root itself.
+None of the exceptions thrown directly by this function or by a `from_json()` that reads the view (the first four
+bullets above) carry a
+[`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) path: the view has no `BasicJsonType` value to point at. An
+exception thrown while converting through `materialize()` (the last bullet) is different: it is thrown by a real
+`BasicJsonType` value, so it **does** carry a `JSON_DIAGNOSTICS` path if `BasicJsonType` was built with it enabled.
+That path is relative to the root of the view's subtree, because `materialize()` builds only the subtree (with parent
+pointers): it is empty if the failing value is the subtree's root itself, and it never is the path within the whole
+document.

 ## Complexity

@@ -22,9 +22,9 @@ Strong guarantee: there are no changes to the view or the document it refers to.
 Throws [`type_error.302`](../../home/exceptions.md#jsonexceptiontype_error302) if the value is not a string; example:
 `"type must be string, but is array"`.

-As for `BasicJsonType`, with [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) the exception names the JSON Pointer
-path of the value within the document, and with [`JSON_DIAGNOSTIC_POSITIONS`](../macros/json_diagnostic_positions.md)
-its bytes in the source text (when [`materialize()`](materialize.md) sets them).
+This exception does not carry a [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) path: the view has no
+`BasicJsonType` value to point at, so the exception is created without one, even if `BasicJsonType` was built with
+`JSON_DIAGNOSTICS` enabled.

 ## Complexity

@@ -22,9 +22,9 @@ Strong guarantee: there are no changes to the view or the document it refers to.
 Throws [`type_error.302`](../../home/exceptions.md#jsonexceptiontype_error302) if the value is not a number; example:
 `"type must be number, but is string"`.

-As for `BasicJsonType`, with [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) the exception names the JSON Pointer
-path of the value within the document, and with [`JSON_DIAGNOSTIC_POSITIONS`](../macros/json_diagnostic_positions.md)
-its bytes in the source text (when [`materialize()`](materialize.md) sets them).
+This exception does not carry a [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) path: the view has no
+`BasicJsonType` value to point at, so the exception is created without one, even if `BasicJsonType` was built with
+`JSON_DIAGNOSTICS` enabled.

 ## Complexity

@@ -73,10 +73,9 @@ Strong guarantee: there are no changes to the view or the document it refers to.
    - [`parse_error.109`](../../home/exceptions.md#jsonexceptionparse_error109) if an array index in `ptr` is not a
      number.

-As for `BasicJsonType`, with [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) these exceptions name the JSON
-Pointer path of the value within the document, and with
-[`JSON_DIAGNOSTIC_POSITIONS`](../macros/json_diagnostic_positions.md) its bytes in the source text (when
-[`materialize()`](materialize.md) sets them).
+None of these exceptions carry a [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) path: the view has no
+`BasicJsonType` value to point at, so the exception is created without one, even if `BasicJsonType` was built with
+`JSON_DIAGNOSTICS` enabled.

 ## Complexity

@@ -61,10 +61,9 @@ Strong guarantee: there are no changes to the view or the document it refers to.
   `default_value` instead of throwing, exactly as [`BasicJsonType::value`](../basic_json/value.md) catches
   `out_of_range` and returns `default_value`.

-As for `BasicJsonType`, with [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) these exceptions name the JSON
-Pointer path of the value within the document, and with
-[`JSON_DIAGNOSTIC_POSITIONS`](../macros/json_diagnostic_positions.md) its bytes in the source text (when
-[`materialize()`](materialize.md) sets them).
+None of these exceptions carry a [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) path: the view has no
+`BasicJsonType` value to point at, so the exception is created without one, even if `BasicJsonType` was built with
+`JSON_DIAGNOSTICS` enabled.

 ## Complexity

@@ -134,21 +134,9 @@ document: `#!cpp auto v = json_document::parse(text).root();` does not compile.
 - **Macros.** [`JSON_STRICT_NUL_HANDLING`](../api/macros/json_strict_nul_handling.md) and
  [`JSON_NOEXCEPTION`](../api/macros/json_noexception.md)/[`JSON_THROW_USER`](../api/macros/json_throw_user.md)
  behave the same way they do for `<nlohmann/json.hpp>`. These are the macros that change what the parser accepts or
-  how it reports errors. Two more macros add context to the exceptions of views, as they do for those of
-  `#!cpp basic_json`:
-
-    - With [`JSON_DIAGNOSTICS`](../api/macros/json_diagnostics.md), an exception names the JSON Pointer path of the
-      value within the document.
-    - With [`JSON_DIAGNOSTIC_POSITIONS`](../api/macros/json_diagnostic_positions.md), an exception names the bytes of
-      the value in the source text.
-
-    A view has neither parent pointers nor stored positions, so both are found from the document's index when the
-    exception is thrown. This takes time linear in the size of the document. One exception has neither:
-    `key()` of an iterator over an array or a primitive value
-    ([`invalid_iterator.207`](../home/exceptions.md#jsonexceptioninvalid_iterator207)), because a view's iterator does
-    not know the value it iterates over.
-
-    The other macros only affect the values `materialize()` produces, through `BasicJsonType`.
+  how it reports errors. The others either do not apply ([`JSON_DIAGNOSTICS`](../api/macros/json_diagnostics.md)
+  needs parent pointers in `basic_json` values) or only affect the values `materialize()` produces, through
+  `BasicJsonType`.

 ## What is different

@@ -179,6 +167,10 @@ document: `#!cpp auto v = json_document::parse(text).root();` does not compile.
  [`at`](../api/basic_json_view/at.md) throws for every missing value.
 - **Duplicate keys: lookups find the first member, `parse()` keeps the last.** See [Duplicate keys](#duplicate-keys)
  below.
+- **No [`JSON_DIAGNOSTICS`](../api/macros/json_diagnostics.md) path.** Exceptions thrown by `basic_json_view`'s own
+  element access and lookup functions never carry the JSON Pointer path `JSON_DIAGNOSTICS` would otherwise add: the
+  view has no `basic_json` value to point at, so the exception is created without one, regardless of how
+  `BasicJsonType` was built.
 - **Ordering comparisons are not provided** by `basic_json_view` — there is no `#!cpp operator<`.
  [`operator==`](../api/basic_json_view/operator_eq.md) and [`operator!=`](../api/basic_json_view/operator_ne.md) are
  provided, though: two views, or a view and a `BasicJsonType` value, compare equal exactly when
@@ -337,10 +329,14 @@ Its body may only use what views and `basic_json` have in common: the type check
 a view does not have; such a type is converted through `materialize()`. A `from_json()` for `json` only is
 converted through `materialize()` as well.

-One thing differs when a `from_json()` reads the view: members looked up by name (`at()`, `value()`, ... and thus
-the macros) find the **first** member with a repeated key, see [Duplicate keys](#duplicate-keys);
-`#!cpp materialize().get<T>()` would see the last one. Containers built from an object, such as `#!cpp std::map`,
-keep the **last** value either way, as [`parse()`](../api/basic_json/parse.md) does.
+Two things differ when a `from_json()` reads the view:
+
+- **Duplicate keys.** Members looked up by name (`at()`, `value()`, ... and thus the macros) find the **first** member
+  with a repeated key, see [Duplicate keys](#duplicate-keys); `#!cpp materialize().get<T>()` would see the last one.
+  Containers built from an object, such as `#!cpp std::map`, keep the **last** value either way, as
+  [`parse()`](../api/basic_json/parse.md) does.
+- **[`JSON_DIAGNOSTICS`](../api/macros/json_diagnostics.md).** Exceptions thrown by the view carry no path to the
+  value.

 `to_json()` is unaffected: it writes `basic_json` values, never views.

@@ -431,28 +431,6 @@ std::nullptr_t exception_context(const View& /*unused*/) noexcept
    return nullptr;
 }

-namespace view
-{
-// the path and bytes of the value of a view (defined in <nlohmann/detail/view/errors.hpp>)
-template<typename View>
-std::string diagnostics_of(const View& v);
-}  // namespace view
-
-// what goes in front of the message of an exception about j: nothing for a
-// basic_json value (exception_context() passes the value itself), the context
-// basic_json would add (JSON_DIAGNOSTICS, JSON_DIAGNOSTIC_POSITIONS) for a view
-template<typename BasicJsonType, enable_if_t<is_basic_json<BasicJsonType>::value, int> = 0>
-const char* exception_prefix(const BasicJsonType& /*unused*/) noexcept
-{
-    return "";
-}
-
-template<typename View, enable_if_t<is_json_view<View>::value, int> = 0>
-std::string exception_prefix(const View& v)
-{
-    return view::diagnostics_of(v);
-}
-
 /*!
@brief throws because @a j does not have the type a conversion expects
@param[in] expected  the expected type(s), e.g. "array" or "binary or array"
@@ -464,7 +442,7 @@ JSON_HEDLEY_NO_RETURN JSON_HEDLEY_NEVER_INLINE void throw_type_must_be(const cha
 {
    static_cast<void>(expected); // unused when JSON_NOEXCEPTION is defined
    static_cast<void>(j);
-    JSON_THROW(type_error::create(exception_id::type_mismatch, concat(exception_prefix(j), "type must be ", expected, ", but is ", j.type_name()), exception_context(j)));
+    JSON_THROW(type_error::create(exception_id::type_mismatch, concat("type must be ", expected, ", but is ", j.type_name()), exception_context(j)));
 }

 /*!
@@ -347,7 +347,7 @@
            return ej_pair.second == j;                                                         \
        });                                                                                     \
        if (it != std::end(m)) e = it->first;                                                   \
-        else ::nlohmann::detail::templated_json_throw<nlohmann::detail::out_of_range>(nlohmann::detail::out_of_range::create(nlohmann::detail::exception_id::value_out_of_range, nlohmann::detail::concat(nlohmann::detail::exception_prefix(j), "enum value out of range for " #ENUM_TYPE ": ", nlohmann::detail::from_json_dump(j)), nlohmann::detail::exception_context(j))); \
+        else ::nlohmann::detail::templated_json_throw<nlohmann::detail::out_of_range>(nlohmann::detail::out_of_range::create(nlohmann::detail::exception_id::value_out_of_range, nlohmann::detail::concat("enum value out of range for " #ENUM_TYPE ": ", nlohmann::detail::from_json_dump(j)), nlohmann::detail::exception_context(j))); \
    }

 // Ugly macros to avoid uglier copy-paste when specializing basic_json. They
@@ -69,7 +69,8 @@ struct parse_failure
 };

 /// FloatType: the number_float_t of the document, whose overflow parse() rejects
-template<typename FloatType, bool Comments, bool TrailingCommas, bool NulIsEnd, bool Sentinel>
+/// Store: false for accept(): the grammar, number, string and UTF-8 checks run as for parse(), but no node is written
+template<typename FloatType, bool Comments, bool TrailingCommas, bool NulIsEnd, bool Sentinel, bool Store>
 class builder
 {
  public:
@@ -245,11 +246,87 @@ class builder
        return p;
    }

+    /// the string from p, the first backslash, control character, ill-formed UTF-8 byte, or the end, checked and not
+    /// decoded (accept() stores nothing, so the arena is not written): the checks, errors and error positions of
+    /// slow_string(), for everything up to the closing quote
+    NLOHMANN_VIEW_NOINLINE decoded check_string(const unsigned char* p)
+    {
+        const unsigned char* const end = m_end;
+        for (;;)
+        {
+            if (p == end)
+            {
+                return failed(error_code::string_missing_quote, p);
+            }
+            const unsigned char c = *p;
+            if (c == '"')
+            {
+                ++p;
+                return decoded{p, 0, 0};
+            }
+            if (c != '\\')
+            {
+                return failed(c < 0x20 ? error_code::string_control_character : error_code::string_utf8, p);
+            }
+            ++p;
+            if (p == end)
+            {
+                return failed(error_code::string_missing_quote, p);
+            }
+            const unsigned char d = *p++;
+            if (d == 'u')
+            {
+                const int cp = hex4(p); // (moves p past the four digits)
+                if (NLOHMANN_VIEW_UNLIKELY(cp < 0))
+                {
+                    return failed(error_code::string_unicode_hex, p);
+                }
+                if (NLOHMANN_VIEW_UNLIKELY((cp & 0xF800) == 0xD800)) // a surrogate
+                {
+                    if (cp >= 0xDC00)
+                    {
+                        return failed(error_code::string_surrogate_low, p);
+                    }
+                    if (end - p < 2 || p[0] != '\\' || p[1] != 'u')
+                    {
+                        return failed(error_code::string_surrogate_high, p);
+                    }
+                    p += 2;
+                    const int lo = hex4(p); // (moves p past the four digits)
+                    if (lo < 0)
+                    {
+                        return failed(error_code::string_unicode_hex, p);
+                    }
+                    if (lo < 0xDC00 || lo > 0xDFFF)
+                    {
+                        return failed(error_code::string_surrogate_high, p);
+                    }
+                }
+            }
+            else if (!(d == '"' || d == '\\' || d == '/' || d == 'b' || d == 'f' || d == 'n' || d == 'r' || d == 't'))
+            {
+                --p;
+                return failed(error_code::string_escape, p);
+            }
+            if (p != end && *p == '\\')
+            {
+                continue; // (escapes in a row: no run of text between them)
+            }
+            p = scan_string_run(p, end); // the text up to the next backslash, quote, control character, or ill-formed UTF-8
+        }
+    }
+
    /// s points to the start of the string, p to a backslash, a control
    /// character, an ill-formed UTF-8 byte, or the end: decode the string into
    /// the arena
    NLOHMANN_VIEW_NOINLINE decoded slow_string(const unsigned char* s, const unsigned char* p)
    {
+        if (!enabled(Store))
+        {
+            // (accept(): the string is checked, not decoded)
+            static_cast<void>(s);
+            return check_string(p);
+        }
        // single-character escapes; 0: invalid (and 'u', handled separately)
        static const std::array<char, 128> simple_escape =
        {
@@ -610,10 +687,13 @@ run_found:

        NLOHMANN_VIEW_ALWAYS_INLINE bool run()
        {
-            cold.m_doc.reserve(estimate_nodes(reinterpret_cast<const char*>(b), static_cast<std::size_t>(e - b)));
-            base = cold.m_doc.nodes;
-            out = base;
-            cap = base + cold.m_doc.node_capacity;
+            if (enabled(Store))
+            {
+                cold.m_doc.reserve(estimate_nodes(reinterpret_cast<const char*>(b), static_cast<std::size_t>(e - b)));
+                base = cold.m_doc.nodes;
+                out = base;
+                cap = base + cold.m_doc.node_capacity;
+            }

            if (e - p >= 3 && p[0] == 0xEF && p[1] == 0xBB && p[2] == 0xBF)
            {
@@ -797,7 +877,10 @@ close_object:
            // an array pays nothing for this)
            if (NLOHMANN_VIEW_UNLIKELY(cur_count >= document_data::index_min_members))
            {
-                cold.note_large_object(cur_idx);
+                if (enabled(Store))
+                {
+                    cold.note_large_object(cur_idx);
+                }
            }

 close_container:
@@ -957,6 +1040,12 @@ indent_done:
        /// an integer's value); two stores on little-endian targets
        NLOHMANN_VIEW_ALWAYS_INLINE node* push_node(node_kind k, std::uint8_t flags, std::uint16_t extra, std::size_t off, std::uint64_t second)
        {
+            if (!enabled(Store))
+            {
+                // accept(): nothing is stored, so what computes the arguments is not run either. base and out stay
+                // null: their difference, which open() takes, is 0.
+                return out;
+            }
            if (NLOHMANN_VIEW_UNLIKELY(out == cap))
            {
                const auto n = static_cast<std::size_t>(out - base);
@@ -1015,9 +1104,12 @@ indent_done:

        NLOHMANN_VIEW_ALWAYS_INLINE void close()
        {
-            node& n = base[cur_idx];
-            n.len = cur_count;
-            n.next = static_cast<std::uint32_t>(out - base) - cur_idx;
+            if (enabled(Store))
+            {
+                node& n = base[cur_idx];
+                n.len = cur_count;
+                n.next = static_cast<std::uint32_t>(out - base) - cur_idx;
+            }
            if (--depth != 0)
            {
                if (NLOHMANN_VIEW_LIKELY(depth <= 64))
@@ -1192,34 +1284,44 @@ indent_done:
 };

 /// run the builder with compile-time options
-template<typename FloatType, bool Comments, bool TrailingCommas, bool NulIsEnd>
+template<typename FloatType, bool Comments, bool TrailingCommas, bool NulIsEnd, bool Store>
 inline bool build_with(document_data& d, const char* src, std::size_t size, bool sentinel, parse_failure& failure)
 {
    if (sentinel)
    {
-        builder<FloatType, Comments, TrailingCommas, NulIsEnd, true> bld(d, src, size);
+        builder<FloatType, Comments, TrailingCommas, NulIsEnd, true, Store> bld(d, src, size);
        const bool ok = bld.run();
        failure = bld.failure();
        return ok;
    }
-    builder<FloatType, Comments, TrailingCommas, NulIsEnd, false> bld(d, src, size);
+    builder<FloatType, Comments, TrailingCommas, NulIsEnd, false, Store> bld(d, src, size);
    const bool ok = bld.run();
    failure = bld.failure();
    return ok;
 }

 /// sentinel: src[size] is readable and 0 (e.g. std::string); FloatType: the
-/// number_float_t of the document
+/// number_float_t of the document; validate_only: accept(), only the result is
+/// used
 template<typename FloatType, bool NulIsEnd>
-inline bool build(document_data& d, const char* src, std::size_t size, bool comments, bool trailing_commas, bool sentinel, parse_failure& failure)
+inline bool build(document_data& d, const char* src, std::size_t size, bool comments, bool trailing_commas, bool sentinel, bool validate_only,
+                  parse_failure& failure)
 {
+    if (validate_only && !comments && !trailing_commas)
+    {
+        // accept() of plain JSON: nothing is stored. The other option sets
+        // could skip the stores just as well; they keep the builder that
+        // stores only so that there are two more instantiations of the parse
+        // loop, not eight.
+        return build_with<FloatType, false, false, NulIsEnd, false>(d, src, size, sentinel, failure);
+    }
    if (comments)
    {
-        return trailing_commas ? build_with<FloatType, true, true, NulIsEnd>(d, src, size, sentinel, failure)
-               : build_with<FloatType, true, false, NulIsEnd>(d, src, size, sentinel, failure);
+        return trailing_commas ? build_with<FloatType, true, true, NulIsEnd, true>(d, src, size, sentinel, failure)
+               : build_with<FloatType, true, false, NulIsEnd, true>(d, src, size, sentinel, failure);
    }
-    return trailing_commas ? build_with<FloatType, false, true, NulIsEnd>(d, src, size, sentinel, failure)
-           : build_with<FloatType, false, false, NulIsEnd>(d, src, size, sentinel, failure);
+    return trailing_commas ? build_with<FloatType, false, true, NulIsEnd, true>(d, src, size, sentinel, failure)
+           : build_with<FloatType, false, false, NulIsEnd, true>(d, src, size, sentinel, failure);
 }

 }  // namespace view
@@ -157,7 +157,7 @@ class editor
        node* const o = own(object);
        if (o->kind != node_kind::object && o->kind != node_kind::null)
        {
-            throw_type_error(site_of(object), exception_id::subscript_wrong_type, "cannot use operator[] with a string argument with ", object.type_name());
+            throw_type_error(exception_id::subscript_wrong_type, "cannot use operator[] with a string argument with ", object.type_name());
        }
        check_utf8(key.data(), key.size());
        const encoded e = encode(std::forward<V>(value));
@@ -208,9 +208,9 @@ class editor
        node* const a = own(array);
        if (a->kind != node_kind::array)
        {
-            throw_type_error(site_of(array), exception_id::subscript_wrong_type, "cannot use operator[] with a numeric argument with ", array.type_name());
+            throw_type_error(exception_id::subscript_wrong_type, "cannot use operator[] with a numeric argument with ", array.type_name());
        }
-        check_index(a, idx, a->len);
+        check_index(idx, a->len);
        const encoded e = encode(std::forward<V>(value));
        node* const slot = const_cast<node*>(nav::value(element_at<true>(m_doc, a, idx))); // NOLINT(cppcoreguidelines-pro-type-const-cast)
        assign(slot, e, a, true);
@@ -225,7 +225,7 @@ class editor
        node* const a = own(array);
        if (a->kind != node_kind::array && a->kind != node_kind::null)
        {
-            throw_type_error(site_of(array), exception_id::push_back_wrong_type, "cannot use push_back() with ", array.type_name());
+            throw_type_error(exception_id::push_back_wrong_type, "cannot use push_back() with ", array.type_name());
        }
        const encoded e = encode(std::forward<V>(value));
        if (a->kind == node_kind::null)
@@ -249,9 +249,9 @@ class editor
        node* const a = own(array);
        if (a->kind != node_kind::array)
        {
-            throw_type_error(site_of(array), exception_id::insert_wrong_type, "cannot use insert() with ", array.type_name());
+            throw_type_error(exception_id::insert_wrong_type, "cannot use insert() with ", array.type_name());
        }
-        check_index(a, idx, a->len + 1);
+        check_index(idx, a->len + 1);
        const encoded e = encode(std::forward<V>(value));
        node* const slot = new_slot(e);
        node* const h = block_of(m_doc, a, 1);
@@ -269,7 +269,7 @@ class editor
        node* const o = own(object);
        if (o->kind != node_kind::object)
        {
-            throw_type_error(site_of(object), exception_id::erase_wrong_type, "cannot use erase() with ", object.type_name());
+            throw_type_error(exception_id::erase_wrong_type, "cannot use erase() with ", object.type_name());
        }
        for (const node* k = nav::first(m_doc, o), *end = nav::end(m_doc, o); k != end; k = document_data::after(k + 1))
        {
@@ -287,9 +287,9 @@ class editor
        node* const a = own(array);
        if (a->kind != node_kind::array)
        {
-            throw_type_error(site_of(array), exception_id::erase_wrong_type, "cannot use erase() with ", array.type_name());
+            throw_type_error(exception_id::erase_wrong_type, "cannot use erase() with ", array.type_name());
        }
-        check_index(a, idx, a->len);
+        check_index(idx, a->len);
        node* const h = block_of(m_doc, a, 0);
        std::memmove(h + 1 + idx, h + 2 + idx, (h->next - 2 - idx) * sizeof(node));
        --h->next;
@@ -316,11 +316,11 @@ class editor
        return const_cast<node*>(v.m_node); // NOLINT(cppcoreguidelines-pro-type-const-cast): the nodes belong to this document
    }

-    void check_index(const node* array, std::size_t idx, std::size_t limit) const
+    static void check_index(std::size_t idx, std::size_t limit)
    {
        if (idx >= limit)
        {
-            throw_array_index_out_of_range(error_site(&m_doc, array), idx);
+            throw_array_index_out_of_range(idx);
        }
    }

@@ -10,15 +10,11 @@

 #include <algorithm> // min
 #include <cstddef> // size_t
-#include <string> // string, to_string
-#include <vector> // vector
+#include <string> // string

 #include <nlohmann/json.hpp>
 #include <nlohmann/detail/view/builder.hpp>
-#include <nlohmann/detail/view/document_data.hpp>
 #include <nlohmann/detail/view/macro_scope.hpp>
-#include <nlohmann/detail/view/materialize.hpp>
-#include <nlohmann/detail/view/node.hpp>

 NLOHMANN_JSON_NAMESPACE_BEGIN
 namespace detail
@@ -26,292 +22,8 @@ namespace detail
 namespace view
 {

-/*!
-@brief the value an exception is about
-
-basic_json passes the value to the exception, which then names its path
-(JSON_DIAGNOSTICS) and its bytes in the source (JSON_DIAGNOSTIC_POSITIONS). A
-view's value has no parent pointer and no stored positions: both are found
-from the document and the node, when the exception is thrown (so only the
-error path pays for them). Without the two macros, a site is empty.
-*/
-class error_site
-{
-  public:
-    error_site() noexcept = default;
-
-#if JSON_DIAGNOSTICS || JSON_DIAGNOSTIC_POSITIONS
-    error_site(const document_data* d, const node* n) noexcept
-        : m_doc(d), m_node(n)
-    {}
-
-    const document_data* doc() const noexcept
-    {
-        return m_doc;
-    }
-    const node* value() const noexcept
-    {
-        return m_node;
-    }
-
-  private:
-    const document_data* m_doc = nullptr;
-    const node* m_node = nullptr;
-#else
-    error_site(const document_data* /*d*/, const node* /*n*/) noexcept {}
-#endif
-};
-
-/// the site of a view's value (the views make this a friend)
-struct view_access
-{
-    template<typename View>
-    static error_site site(const View& v) noexcept
-    {
-        return error_site(v.m_doc, v.m_node);
-    }
-};
-
-template<typename View>
-error_site site_of(const View& v) noexcept
-{
-    static_assert(is_json_view<View>::value, "the site of a value is only defined for views");
-    return view_access::site(v);
-}
-
-#if JSON_DIAGNOSTICS
-/*!
-@brief the JSON pointer tokens from the root of document @a d to node @a target
-
-Nodes have no parent index, so the path is found by descending from the root:
-before the first edit, only into the subtree that contains the target (a
-container spans the next `next` nodes); after edits, elements can live in
-other sequences, so every container is searched. Iterative (the nesting depth
-is limited by memory only). False if the target is not found (then tokens is
-unspecified).
-*/
-template<bool Editable>
-bool value_path(const document_data& d, const node* target, std::vector<std::string>& tokens)
-{
-    using nav = navigation<Editable>;
-    struct frame
-    {
-        const node* pos;
-        const node* end;
-        std::size_t index;
-        bool object;
-    };
-    const node* const root = d.nodes;
-    if (target == root)
-    {
-        return true;
-    }
-    if (!is_container(*root))
-    {
-        return false;
-    }
-    std::vector<frame> stack;
-    stack.push_back(frame{nav::first(d, root), nav::end(d, root), 0, root->kind == node_kind::object});
-    // (tokens[i] leads from stack[i] to stack[i + 1], or to the target)
-    for (;;)
-    {
-        // (f is not used after the stack changes: pop_back() below, push_back() at the end)
-        frame& f = stack.back();
-        if (f.pos == f.end)
-        {
-            stack.pop_back();
-            if (stack.empty())
-            {
-                return false;
-            }
-            tokens.pop_back();
-            continue;
-        }
-        const node* entry = f.pos;
-        std::string token;
-        if (f.object)
-        {
-            // (as basic_json: the key up to a null byte)
-            token.assign(d.str(*entry), entry->len);
-            const std::size_t nul = token.find('\0');
-            if (nul != std::string::npos)
-            {
-                token.resize(nul);
-            }
-            ++entry;
-        }
-        else
-        {
-            token = std::to_string(f.index);
-        }
-        const node* const child = nav::value(entry);
-        if (child == target)
-        {
-            tokens.push_back(token);
-            return true;
-        }
-        f.pos = document_data::after(entry);
-        ++f.index;
-        if (is_container(*child) && (nav::editable() || (target > child && target < child + child->next)))
-        {
-            tokens.push_back(token);
-            stack.push_back(frame{nav::first(d, child), nav::end(d, child), 0, child->kind == node_kind::object});
-        }
-    }
-}
-#endif
-
-#if JSON_DIAGNOSTIC_POSITIONS
-/*!
-@brief the bytes [start, end) of node @a n in the source, as materialize() sets them
-
-Scalars as position_source::set_scalar; an array or object from its opening
-bracket to its closing bracket, which is found by following the chain of last
-elements to a scalar (or an empty container) and scanning from there to the
-closing brackets. None (npos) for values written by edits, and for containers
-whose last element has none, as with materialize().
-*/
-template<bool Editable>
-void value_range(const document_data& d, const node* n, std::size_t& start, std::size_t& end)
-{
-    using nav = navigation<Editable>;
-    position_source p;
-    start = std::string::npos;
-    end = std::string::npos;
-    if (!is_container(*n))
-    {
-        p.set_scalar(d, *n);
-        start = p.start;
-        end = p.end;
-        return;
-    }
-    if ((n->flags & node_flags::is_new) != 0 || n->off >= d.size)
-    {
-        return;
-    }
-    // the open brackets: n, then the last element as long as it is a non-empty container
-    std::size_t closing = 0;
-    std::size_t pos = std::string::npos;
-    for (const node* c = n;;)
-    {
-        if (!is_container(*c))
-        {
-            p.set_scalar(d, *c);
-            pos = p.end;
-            break;
-        }
-        if ((c->flags & node_flags::is_new) != 0 || c->off >= d.size)
-        {
-            return;
-        }
-        ++closing;
-        const node* const first = nav::first(d, c);
-        const node* const last_end = nav::end(d, c);
-        if (first == last_end)
-        {
-            pos = std::size_t{c->off} + 1;
-            break;
-        }
-        const std::size_t value_offset = c->kind == node_kind::object ? 1 : 0;
-        const node* last = first;
-        for (const node* e = document_data::after(first + value_offset); e != last_end; e = document_data::after(e + value_offset))
-        {
-            last = e;
-        }
-        c = nav::value(last + value_offset);
-    }
-    for (; closing != 0 && pos != std::string::npos; --closing)
-    {
-        pos = position_source::container_end(d.base[0], d.size, pos);
-    }
-    if (pos != std::string::npos)
-    {
-        start = n->off;
-        end = pos;
-    }
-}
-#endif
-
-/// the context basic_json puts in front of the message of an exception about
-/// a value: "(/path) " with JSON_DIAGNOSTICS (none for the root), then
-/// "(bytes a-b) " with JSON_DIAGNOSTIC_POSITIONS (with JSON_DIAGNOSTICS, only
-/// if there is a path)
-///
-/// This and the throw helpers that take an error_site are templates, so that
-/// the path and range code is instantiated only where an exception can be
-/// thrown: instantiated in every translation unit (as a non-template inline
-/// function makes it), it changed GCC's early inlining of unrelated view
-/// functions, so that GCC 13 no longer inlined a recursive walk over a view
-/// into itself (2.7 times the instructions).
-#if JSON_DIAGNOSTICS || JSON_DIAGNOSTIC_POSITIONS
-template<typename Unused = void>
-std::string diagnostics(const error_site site)
-{
-    if (site.doc() == nullptr || site.value() == nullptr)
-    {
-        return "";
-    }
-    const document_data& d = *site.doc();
-    const bool edited = d.edits != nullptr;
-    std::string context;
-#if JSON_DIAGNOSTICS
-    std::vector<std::string> tokens;
-    const bool found = edited ? value_path<true>(d, site.value(), tokens) : value_path<false>(d, site.value(), tokens);
-    if (!found || tokens.empty())
-    {
-        return "";
-    }
-    std::string path;
-    for (const std::string& token : tokens)
-    {
-        path.push_back('/');
-        path += detail::escape(token);
-    }
-    context = concat('(', path, ") ");
-#endif
-#if JSON_DIAGNOSTIC_POSITIONS
-    std::size_t start = 0;
-    std::size_t end = 0;
-    if (edited)
-    {
-        value_range<true>(d, site.value(), start, end);
-    }
-    else
-    {
-        value_range<false>(d, site.value(), start, end);
-    }
-    if (start != std::string::npos && end != std::string::npos)
-    {
-        context += concat("(bytes ", std::to_string(start), "-", std::to_string(end), ") ");
-    }
-#endif
-    return context;
-}
-#else
-template<typename Unused = void>
-std::string diagnostics(const error_site /*site*/)
-{
-    return "";
-}
-#endif
-
-/// the context of an exception about view @a v (see exception_prefix())
-template<typename View>
-std::string diagnostics_of(const View& v)
-{
-    return diagnostics<>(site_of(v));
-}
-
 // Exceptions are thrown out of line, so that the accessors that may throw stay
-// small enough to be inlined. The overloads with an error_site put its context
-// in front of the message.
-//
-// The overloads without one are for exceptions that are not about a value of a
-// document: limits and invalid input of the editing and image functions, a
-// discarded view (it has no node), a view of another document (its path would
-// be one in that document), and those that basic_json creates without a
-// context too (the errors of json_pointer, invalid UTF-8). The one exception
-// about a value that has no site is key(), see view_iterator::key().
+// small enough to be inlined.

 [[noreturn]] NLOHMANN_VIEW_NOINLINE inline void throw_type_error(exception_id id, const char* prefix, const char* type)
 {
@@ -333,24 +45,6 @@ std::string diagnostics_of(const View& v)
    NLOHMANN_VIEW_THROW(invalid_iterator::create(id, msg, nullptr));
 }

-template<typename Unused = void>
-[[noreturn]] NLOHMANN_VIEW_NOINLINE void throw_type_error(const error_site site, exception_id id, const char* prefix, const char* type)
-{
-    NLOHMANN_VIEW_THROW(type_error::create(id, concat(diagnostics<>(site), prefix, type), nullptr));
-}
-
-template<typename Unused = void>
-[[noreturn]] NLOHMANN_VIEW_NOINLINE void throw_out_of_range(const error_site site, exception_id id, const std::string& msg)
-{
-    NLOHMANN_VIEW_THROW(out_of_range::create(id, concat(diagnostics<>(site), msg), nullptr));
-}
-
-template<typename Unused = void>
-[[noreturn]] NLOHMANN_VIEW_NOINLINE void throw_invalid_iterator(const error_site site, exception_id id, const char* msg)
-{
-    NLOHMANN_VIEW_THROW(invalid_iterator::create(id, concat(diagnostics<>(site), msg), nullptr));
-}
-
 /// a parse error without a position (as those of json_pointer)
 [[noreturn]] NLOHMANN_VIEW_NOINLINE inline void throw_parse_error(exception_id id, const std::string& msg)
 {
@@ -359,23 +53,22 @@ template<typename Unused = void>

 /// out_of_range.401: the array index @a idx is not below the size
 template<typename Index>
-[[noreturn]] NLOHMANN_VIEW_NOINLINE void throw_array_index_out_of_range(const error_site site, const Index idx)
+[[noreturn]] NLOHMANN_VIEW_NOINLINE void throw_array_index_out_of_range(const Index idx)
 {
-    throw_out_of_range(site, exception_id::array_index_out_of_range, concat("array index ", std::to_string(idx), " is out of range"));
+    throw_out_of_range(exception_id::array_index_out_of_range, concat("array index ", std::to_string(idx), " is out of range"));
 }

 /// out_of_range.402: the JSON Pointer token '-' of an array of @a size elements
-template<typename Unused = void>
-[[noreturn]] NLOHMANN_VIEW_NOINLINE void throw_array_index_past_end(const error_site site, std::size_t size)
+[[noreturn]] NLOHMANN_VIEW_NOINLINE inline void throw_array_index_past_end(std::size_t size)
 {
-    throw_out_of_range(site, exception_id::pointer_past_the_end_index, concat("array index '-' (", std::to_string(size), ") is out of range"));
+    throw_out_of_range(exception_id::pointer_past_the_end_index, concat("array index '-' (", std::to_string(size), ") is out of range"));
 }

 /// out_of_range.403: the object has no member @a key
 template<typename Key>
-[[noreturn]] NLOHMANN_VIEW_NOINLINE void throw_key_not_found(const error_site site, const Key& key)
+[[noreturn]] NLOHMANN_VIEW_NOINLINE void throw_key_not_found(const Key& key)
 {
-    throw_out_of_range(site, exception_id::key_not_found, concat("key '", key, "' not found"));
+    throw_out_of_range(exception_id::key_not_found, concat("key '", key, "' not found"));
 }

 /// SAX handler of the error replay: accepts every event without storing it,
@@ -105,10 +105,7 @@ class view_iterator
    }

    /// the key of the current object member; throws invalid_iterator.207 for
-    /// other iterators, like basic_json's iterators (but without the context
-    /// JSON_DIAGNOSTICS and JSON_DIAGNOSTIC_POSITIONS add: the iterator does not
-    /// know the value it iterates over, and keeping it would make iterators
-    /// larger, which keeps GCC from inlining recursive walks)
+    /// other iterators, like basic_json's iterators
    string_view_t key() const
    {
        if (NLOHMANN_VIEW_UNLIKELY(m_value_offset == 0))
@@ -44,7 +44,6 @@ index_status array_index(const StringType& s, std::size_t& idx) noexcept
 }

 /// throws the exception json_pointer::array_index throws for this status
-/// (without a context, as json_pointer::array_index)
 template<typename StringType>
 [[noreturn]] NLOHMANN_VIEW_NOINLINE void throw_array_index_error(index_status status, const StringType& s)
 {
@@ -84,7 +83,7 @@ View resolve_pointer(View cur, const Tokens& tokens, pointer_mode mode)
            {
                if (mode == pointer_mode::checked)
                {
-                    throw_key_not_found(site_of(cur), token);
+                    throw_key_not_found(token);
                }
                return View();
            }
@@ -96,7 +95,7 @@ View resolve_pointer(View cur, const Tokens& tokens, pointer_mode mode)
            {
                if (throwing)
                {
-                    throw_array_index_past_end(site_of(cur), cur.size());
+                    throw_array_index_past_end(cur.size());
                }
                return View();
            }
@@ -115,7 +114,7 @@ View resolve_pointer(View cur, const Tokens& tokens, pointer_mode mode)
            {
                if (mode == pointer_mode::checked)
                {
-                    throw_array_index_out_of_range(site_of(cur), idx);
+                    throw_array_index_out_of_range(idx);
                }
                return View();
            }
@@ -125,7 +124,7 @@ View resolve_pointer(View cur, const Tokens& tokens, pointer_mode mode)
        {
            if (throwing)
            {
-                throw_out_of_range(site_of(cur), exception_id::pointer_unresolved, concat("unresolved reference token '", token, "'"));
+                throw_out_of_range(exception_id::pointer_unresolved, concat("unresolved reference token '", token, "'"));
            }
            return View();
        }
@@ -60,7 +60,7 @@ NLOHMANN_VIEW_ALWAYS_INLINE T arithmetic_value(const document_data& d, const nod
        case value_t::binary:
        case value_t::discarded:
        default:
-            throw_type_error(error_site(&d, &n), exception_id::type_mismatch, "type must be number, but is ", value_type_name(static_cast<value_t>(n.kind)));
+            throw_type_error(exception_id::type_mismatch, "type must be number, but is ", value_type_name(static_cast<value_t>(n.kind)));
    }
 }

@@ -70,7 +70,7 @@ std::vector<U, A> vector_value(const View& v)
 {
    if (NLOHMANN_VIEW_UNLIKELY(!v.is_array()))
    {
-        throw_type_error(site_of(v), exception_id::type_mismatch, "type must be array, but is ", v.type_name());
+        throw_type_error(exception_id::type_mismatch, "type must be array, but is ", v.type_name());
    }
    std::vector<U, A> r;
    r.reserve(v.size());
@@ -88,7 +88,7 @@ Map map_value(const View& v)
 {
    if (NLOHMANN_VIEW_UNLIKELY(!v.is_object()))
    {
-        throw_type_error(site_of(v), exception_id::type_mismatch, "type must be object, but is ", v.type_name());
+        throw_type_error(exception_id::type_mismatch, "type must be object, but is ", v.type_name());
    }
    Map r;
    for (auto it = v.begin(); it != v.end(); ++it)
@@ -285,7 +285,7 @@ class basic_json_view
            {
                return {};
            }
-            detail::view::throw_type_error(site(), detail::exception_id::subscript_wrong_type, "cannot use operator[] with a string argument with ", type_name());
+            detail::view::throw_type_error(detail::exception_id::subscript_wrong_type, "cannot use operator[] with a string argument with ", type_name());
        }
        return lookup(key);
    }
@@ -311,7 +311,7 @@ class basic_json_view
            {
                return {};
            }
-            detail::view::throw_type_error(site(), detail::exception_id::subscript_wrong_type, "cannot use operator[] with a numeric argument with ", type_name());
+            detail::view::throw_type_error(detail::exception_id::subscript_wrong_type, "cannot use operator[] with a numeric argument with ", type_name());
        }
        return idx < m_node->len ? element(idx) : basic_json_view();
    }
@@ -344,12 +344,12 @@ class basic_json_view
    {
        if (NLOHMANN_VIEW_UNLIKELY(!is_object()))
        {
-            detail::view::throw_type_error(site(), detail::exception_id::at_wrong_type, "cannot use at() with ", type_name());
+            detail::view::throw_type_error(detail::exception_id::at_wrong_type, "cannot use at() with ", type_name());
        }
        const basic_json_view r = lookup(key);
        if (NLOHMANN_VIEW_UNLIKELY(r.is_discarded()))
        {
-            detail::view::throw_key_not_found(site(), std::string(key.data(), key.size()));
+            detail::view::throw_key_not_found(std::string(key.data(), key.size()));
        }
        return r;
    }
@@ -370,11 +370,11 @@ class basic_json_view
    {
        if (NLOHMANN_VIEW_UNLIKELY(!is_array()))
        {
-            detail::view::throw_type_error(site(), detail::exception_id::at_wrong_type, "cannot use at() with ", type_name());
+            detail::view::throw_type_error(detail::exception_id::at_wrong_type, "cannot use at() with ", type_name());
        }
        if (NLOHMANN_VIEW_UNLIKELY(idx >= m_node->len))
        {
-            detail::view::throw_array_index_out_of_range(site(), idx);
+            detail::view::throw_array_index_out_of_range(idx);
        }
        return element(idx);
    }
@@ -402,7 +402,7 @@ class basic_json_view
    {
        if (NLOHMANN_VIEW_UNLIKELY(!is_object()))
        {
-            detail::view::throw_type_error(site(), detail::exception_id::value_wrong_type, "cannot use value() with ", type_name());
+            detail::view::throw_type_error(detail::exception_id::value_wrong_type, "cannot use value() with ", type_name());
        }
        const basic_json_view r = lookup(key);
        return r.is_discarded() ? default_value : r.template get<T>();
@@ -412,7 +412,7 @@ class basic_json_view
    {
        if (NLOHMANN_VIEW_UNLIKELY(!is_object()))
        {
-            detail::view::throw_type_error(site(), detail::exception_id::value_wrong_type, "cannot use value() with ", type_name());
+            detail::view::throw_type_error(detail::exception_id::value_wrong_type, "cannot use value() with ", type_name());
        }
        // (the default is made only if there is no such member)
        const basic_json_view r = lookup(key);
@@ -427,7 +427,7 @@ class basic_json_view
    {
        if (NLOHMANN_VIEW_UNLIKELY(!is_structured()))
        {
-            detail::view::throw_type_error(site(), detail::exception_id::value_wrong_type, "cannot use value() with ", type_name());
+            detail::view::throw_type_error(detail::exception_id::value_wrong_type, "cannot use value() with ", type_name());
        }
        const basic_json_view r = detail::view::resolve_pointer(*this, detail::json_pointer_access::reference_tokens(ptr), detail::view::pointer_mode::value);
        return r.is_discarded() ? default_value : r.template get<T>();
@@ -437,7 +437,7 @@ class basic_json_view
    {
        if (NLOHMANN_VIEW_UNLIKELY(!is_structured()))
        {
-            detail::view::throw_type_error(site(), detail::exception_id::value_wrong_type, "cannot use value() with ", type_name());
+            detail::view::throw_type_error(detail::exception_id::value_wrong_type, "cannot use value() with ", type_name());
        }
        const basic_json_view r = detail::view::resolve_pointer(*this, detail::json_pointer_access::reference_tokens(ptr), detail::view::pointer_mode::value);
        return r.is_discarded() ? string_t(default_value) : r.template get<string_t>();
@@ -450,7 +450,7 @@ class basic_json_view
        const iterator it = begin();
        if (NLOHMANN_VIEW_UNLIKELY(it == end()))
        {
-            detail::view::throw_invalid_iterator(site(), detail::exception_id::iterator_value_unavailable, "cannot get value");
+            detail::view::throw_invalid_iterator(detail::exception_id::iterator_value_unavailable, "cannot get value");
        }
        return *it;
    }
@@ -606,7 +606,7 @@ class basic_json_view
    {
        if (NLOHMANN_VIEW_UNLIKELY(!is_string()))
        {
-            detail::view::throw_type_error(site(), detail::exception_id::type_mismatch, "type must be string, but is ", type_name());
+            detail::view::throw_type_error(detail::exception_id::type_mismatch, "type must be string, but is ", type_name());
        }
        return {m_doc->str(*m_node), m_node->len};
    }
@@ -618,7 +618,7 @@ class basic_json_view
    {
        if (NLOHMANN_VIEW_UNLIKELY(!is_number()))
        {
-            detail::view::throw_type_error(site(), detail::exception_id::type_mismatch, "type must be number, but is ", type_name());
+            detail::view::throw_type_error(detail::exception_id::type_mismatch, "type must be number, but is ", type_name());
        }
        return {m_doc->str(*m_node), detail::view::number_length(*m_node)};
    }
@@ -764,19 +764,12 @@ class basic_json_view
    template<typename, view_mode> friend class basic_json_view;
    template<typename, typename> friend class detail::view::editor;
    template<typename, typename> friend class detail::view::view_side;
-    friend struct detail::view::view_access;
    friend iterator;

    basic_json_view(const document_data* d, const node* n) noexcept
        : m_doc(d), m_node(n)
    {}

-    /// this value as the context of an exception
-    detail::view::error_site site() const noexcept
-    {
-        return detail::view::error_site(m_doc, m_node);
-    }
-
    using json_side_t = detail::view::json_side<BasicJsonType, string_view_t>;

    static detail::view::view_side<BasicJsonType, basic_json_view> side(const basic_json_view& v) noexcept
@@ -883,7 +876,7 @@ class basic_json_view
    {
        if (NLOHMANN_VIEW_UNLIKELY(!is_boolean()))
        {
-            detail::view::throw_type_error(site(), detail::exception_id::type_mismatch, "type must be boolean, but is ", type_name());
+            detail::view::throw_type_error(detail::exception_id::type_mismatch, "type must be boolean, but is ", type_name());
        }
        return (m_node->flags & detail::view::node_flags::is_true) != 0;
    }
@@ -893,7 +886,7 @@ class basic_json_view
    {
        if (NLOHMANN_VIEW_UNLIKELY(m_node == nullptr))
        {
-            detail::view::throw_type_error(site(), detail::exception_id::type_mismatch, "type must be number, but is ", type_name());
+            detail::view::throw_type_error(detail::exception_id::type_mismatch, "type must be number, but is ", type_name());
        }
        return detail::view::arithmetic_value<T, BasicJsonType>(*m_doc, *m_node);
    }
@@ -902,7 +895,7 @@ class basic_json_view
    {
        if (NLOHMANN_VIEW_UNLIKELY(!is_null()))
        {
-            detail::view::throw_type_error(site(), detail::exception_id::type_mismatch, "type must be null, but is ", type_name());
+            detail::view::throw_type_error(detail::exception_id::type_mismatch, "type must be null, but is ", type_name());
        }
        return nullptr;
    }
@@ -1067,7 +1060,7 @@ class basic_json_document
                                     const bool ignore_trailing_commas = false)
    {
        basic_json_document d;
-        d.read_range(first, last, allow_exceptions, ignore_comments, ignore_trailing_commas);
+        d.read_range(first, last, error_mode(allow_exceptions), ignore_comments, ignore_trailing_commas);
        return d;
    }

@@ -1082,7 +1075,7 @@ class basic_json_document
        basic_json_document d;
        std::string buf;
        append_input(buf, std::forward<InputType>(input));
-        d.build_owned(std::move(buf), allow_exceptions, ignore_comments, ignore_trailing_commas);
+        d.build_owned(std::move(buf), error_mode(allow_exceptions), ignore_comments, ignore_trailing_commas);
        return d;
    }

@@ -1095,7 +1088,8 @@ class basic_json_document
    static bool accept(InputType&& input, const bool ignore_comments = false, const bool ignore_trailing_commas = false)
    {
        basic_json_document d;
-        d.read(std::forward<InputType>(input), false, ignore_comments, ignore_trailing_commas);
+        d.read_kind(std::forward<InputType>(input), on_error::validate, ignore_comments, ignore_trailing_commas,
+                    std::integral_constant<detail::view::input_kind, detail::view::classify_input<InputType>::value> {});
        return !d.is_discarded();
    }

@@ -1111,7 +1105,7 @@ class basic_json_document
              const bool ignore_comments = false,
              const bool ignore_trailing_commas = false)
    {
-        read_kind(std::forward<InputType>(input), allow_exceptions, ignore_comments, ignore_trailing_commas,
+        read_kind(std::forward<InputType>(input), error_mode(allow_exceptions), ignore_comments, ignore_trailing_commas,
                  std::integral_constant<detail::view::input_kind, detail::view::classify_input<InputType>::value> {});
    }

@@ -1316,7 +1310,7 @@ class basic_json_document
    template<typename I, typename V, typename std::enable_if<detail::view::is_non_bool_integral<I>::value, int>::type = 0>
    view_type set(view_type array, I idx, V && value)
    {
-        return editor().set(array, index(array, idx), std::forward<V>(value));
+        return editor().set(array, index(idx), std::forward<V>(value));
    }

    /// set the value at a JSON pointer: its parent must exist; an object
@@ -1353,7 +1347,7 @@ class basic_json_document
                const std::size_t idx = pointer_index(token);
                if (idx >= 0xFFFFFFFFu)
                {
-                    detail::view::throw_array_index_out_of_range(detail::view::site_of(parent), idx);
+                    detail::view::throw_array_index_out_of_range(idx);
                }
                for (std::size_t i = 0; i < idx; ++i)
                {
@@ -1387,7 +1381,7 @@ class basic_json_document
    template<typename I, typename V, typename std::enable_if<detail::view::is_non_bool_integral<I>::value, int>::type = 0>
    view_type insert(view_type array, I idx, V && value)
    {
-        return editor().insert(array, index(array, idx), std::forward<V>(value));
+        return editor().insert(array, index(idx), std::forward<V>(value));
    }

    /// remove all members with this key; returns their number
@@ -1400,7 +1394,7 @@ class basic_json_document
    template<typename I, typename std::enable_if<detail::view::is_non_bool_integral<I>::value, int>::type = 0>
    void erase(view_type array, I idx)
    {
-        editor().erase(array, index(array, idx));
+        editor().erase(array, index(idx));
    }

    /// remove the value at a JSON pointer; returns the number of removed
@@ -1434,25 +1428,25 @@ class basic_json_document
        return detail::view::editor<BasicJsonType, view_type>(*m_data);
    }

-    /// an index into @a array (out_of_range.401 if negative)
+    /// an index (out_of_range.401 if negative)
    template<typename I>
-    static std::size_t index(const view_type& array, I idx)
+    static std::size_t index(I idx)
    {
-        return index(array, idx, std::is_signed<I> {});
+        return index(idx, std::is_signed<I> {});
    }

    template<typename I>
-    static std::size_t index(const view_type& array, I idx, std::true_type /*signed*/)
+    static std::size_t index(I idx, std::true_type /*signed*/)
    {
        if (idx < 0)
        {
-            detail::view::throw_array_index_out_of_range(detail::view::site_of(array), idx);
+            detail::view::throw_array_index_out_of_range(idx);
        }
        return static_cast<std::size_t>(idx);
    }

    template<typename I>
-    static std::size_t index(const view_type& /*array*/, I idx, std::false_type /*unsigned*/)
+    static std::size_t index(I idx, std::false_type /*unsigned*/)
    {
        return static_cast<std::size_t>(idx);
    }
@@ -1470,6 +1464,22 @@ class basic_json_document
        return idx;
    }

+    /// what a failed parse does
+    enum class on_error : std::uint8_t
+    {
+        discard, ///< the document is discarded
+        raise,   ///< parse_error is thrown
+        validate ///< accept(): the document is discarded, and no node is stored while parsing
+    };
+
+    static on_error error_mode(bool allow_exceptions) noexcept
+    {
+        return allow_exceptions ? on_error::raise : on_error::discard;
+    }
+
+    /// NulIsEnd of the builder: a null byte ends the input unless strict_nul_handling
+    static constexpr bool nul_is_end = !detail::abi_config::strict_nul_handling;
+
    /// create the storage (sized for the input) on first use
    void ensure_data(const char* src, std::size_t size)
    {
@@ -1481,7 +1491,7 @@ class basic_json_document

    /// parse a buffer the document takes ownership of (it replaces the
    /// previous owned copy)
-    void build_owned(std::string&& buf, bool allow_exceptions, bool comments, bool trailing_commas)
+    void build_owned(std::string&& buf, on_error allow_exceptions, bool comments, bool trailing_commas)
    {
        ensure_data(buf.data(), buf.size());
        m_data->owned = std::move(buf);
@@ -1491,7 +1501,7 @@ class basic_json_document
    /// parse a copy of the input; the copy is appended to the cleared owned
    /// buffer, so that its capacity is reused
    template<typename T>
-    void build_copy(T&& input, bool allow_exceptions, bool comments, bool trailing_commas)
+    void build_copy(T&& input, on_error allow_exceptions, bool comments, bool trailing_commas)
    {
        if (!m_data)
        {
@@ -1512,7 +1522,7 @@ class basic_json_document
    }

    /// sentinel: src[size] is readable and 0 (std::string, C strings)
-    void build(const char* src, std::size_t size, bool allow_exceptions, bool comments, bool trailing_commas, bool owned, bool sentinel)
+    void build(const char* src, std::size_t size, on_error allow_exceptions, bool comments, bool trailing_commas, bool owned, bool sentinel)
    {
        ensure_data(src, size);
        document_data& d = *m_data;
@@ -1539,7 +1549,8 @@ class basic_json_document
        }
        else
        {
-            ok = detail::view::build < typename BasicJsonType::number_float_t, !detail::abi_config::strict_nul_handling > (d, src, size, comments, trailing_commas, sentinel, failure);
+            ok = detail::view::build<typename BasicJsonType::number_float_t, nul_is_end>(d, src, size, comments, trailing_commas, sentinel,
+                 allow_exceptions == on_error::validate, failure);
        }
        if (NLOHMANN_VIEW_LIKELY(ok))
        {
@@ -1552,7 +1563,7 @@ class basic_json_document
            return;
        }
        std::vector<std::uint32_t>().swap(d.large_objects);
-        if (allow_exceptions)
+        if (allow_exceptions == on_error::raise)
        {
            detail::view::throw_parse_failure<BasicJsonType>(failure, src, size, comments, trailing_commas);
        }
@@ -1560,13 +1571,13 @@ class basic_json_document

    // --- input dispatch (see detail::view::input_kind) ---

-    void read_kind(std::string&& s, bool ae, bool c, bool tc, std::integral_constant<input_kind, input_kind::move_string> /*unused*/)
+    void read_kind(std::string&& s, on_error ae, bool c, bool tc, std::integral_constant<input_kind, input_kind::move_string> /*unused*/)
    {
        build_owned(std::move(s), ae, c, tc);
    }

    template<typename CharT>
-    void read_kind(CharT* s, bool ae, bool c, bool tc, std::integral_constant<input_kind, input_kind::c_string> /*unused*/)
+    void read_kind(CharT* s, on_error ae, bool c, bool tc, std::integral_constant<input_kind, input_kind::c_string> /*unused*/)
    {
        if (s == nullptr)
        {
@@ -1580,7 +1591,7 @@ class basic_json_document
    }

    template<typename Array>
-    void read_kind(Array& a, bool ae, bool c, bool tc, std::integral_constant<input_kind, input_kind::char_array> /*unused*/)
+    void read_kind(Array& a, on_error ae, bool c, bool tc, std::integral_constant<input_kind, input_kind::char_array> /*unused*/)
    {
        using CharT = typename std::remove_cv<typename std::remove_extent<Array>::type>::type;
        const std::size_t n = std::extent<Array>::value;
@@ -1591,7 +1602,7 @@ class basic_json_document
    }

    template<typename T>
-    void read_kind(const T& s, bool ae, bool c, bool tc, std::integral_constant<input_kind, input_kind::borrow_range> /*unused*/)
+    void read_kind(const T& s, on_error ae, bool c, bool tc, std::integral_constant<input_kind, input_kind::borrow_range> /*unused*/)
    {
        // std::basic_string guarantees data()[size()] == 0: use it as sentinel
        const auto size = static_cast<std::size_t>(s.size());
@@ -1600,13 +1611,13 @@ class basic_json_document
    }

    template<typename T>
-    void read_kind(const T& s, bool ae, bool c, bool tc, std::integral_constant<input_kind, input_kind::copy_range> /*unused*/)
+    void read_kind(const T& s, on_error ae, bool c, bool tc, std::integral_constant<input_kind, input_kind::copy_range> /*unused*/)
    {
        build_copy(s, ae, c, tc);
    }

    template<typename CharT>
-    void read_kind(CharT* s, bool ae, bool c, bool tc, std::integral_constant<input_kind, input_kind::wide_c_string> /*unused*/)
+    void read_kind(CharT* s, on_error ae, bool c, bool tc, std::integral_constant<input_kind, input_kind::wide_c_string> /*unused*/)
    {
        if (s == nullptr)
        {
@@ -1618,13 +1629,13 @@ class basic_json_document
    }

    template<typename T>
-    void read_kind(T&& input, bool ae, bool c, bool tc, std::integral_constant<input_kind, input_kind::adapter> /*unused*/)
+    void read_kind(T&& input, on_error ae, bool c, bool tc, std::integral_constant<input_kind, input_kind::adapter> /*unused*/)
    {
        build_copy(std::forward<T>(input), ae, c, tc);
    }

    template<typename IteratorType>
-    void read_range(IteratorType first, IteratorType last, bool ae, bool c, bool tc)
+    void read_range(IteratorType first, IteratorType last, on_error ae, bool c, bool tc)
    {
        using value_type = typename std::remove_cv<typename std::iterator_traits<IteratorType>::value_type>::type;
        // borrow the range where the library's input adapter scans it as one
@@ -1635,14 +1646,14 @@ class basic_json_document
    }

    template<typename IteratorType>
-    void read_range_impl(IteratorType first, IteratorType last, bool ae, bool c, bool tc, std::true_type /*contiguous bytes*/)
+    void read_range_impl(IteratorType first, IteratorType last, on_error ae, bool c, bool tc, std::true_type /*contiguous bytes*/)
    {
        const auto size = static_cast<std::size_t>(std::distance(first, last));
        build(size == 0 ? "" : reinterpret_cast<const char*>(&*first), size, ae, c, tc, false, size == 0); // NOLINT(cppcoreguidelines-pro-type-reinterpret-cast)
    }

    template<typename IteratorType>
-    void read_range_impl(IteratorType first, IteratorType last, bool ae, bool c, bool tc, std::false_type /*other*/)
+    void read_range_impl(IteratorType first, IteratorType last, on_error ae, bool c, bool tc, std::false_type /*other*/)
    {
        build_copy(detail::view::make_adapter_input(detail::input_adapter(first, last)), ae, c, tc);
    }
@@ -2720,7 +2720,7 @@ JSON_HEDLEY_DIAGNOSTIC_POP
            return ej_pair.second == j;                                                         \
        });                                                                                     \
        if (it != std::end(m)) e = it->first;                                                   \
-        else ::nlohmann::detail::templated_json_throw<nlohmann::detail::out_of_range>(nlohmann::detail::out_of_range::create(nlohmann::detail::exception_id::value_out_of_range, nlohmann::detail::concat(nlohmann::detail::exception_prefix(j), "enum value out of range for " #ENUM_TYPE ": ", nlohmann::detail::from_json_dump(j)), nlohmann::detail::exception_context(j))); \
+        else ::nlohmann::detail::templated_json_throw<nlohmann::detail::out_of_range>(nlohmann::detail::out_of_range::create(nlohmann::detail::exception_id::value_out_of_range, nlohmann::detail::concat("enum value out of range for " #ENUM_TYPE ": ", nlohmann::detail::from_json_dump(j)), nlohmann::detail::exception_context(j))); \
    }

 // Ugly macros to avoid uglier copy-paste when specializing basic_json. They
@@ -5928,28 +5928,6 @@ std::nullptr_t exception_context(const View& /*unused*/) noexcept
    return nullptr;
 }

-namespace view
-{
-// the path and bytes of the value of a view (defined in <nlohmann/detail/view/errors.hpp>)
-template<typename View>
-std::string diagnostics_of(const View& v);
-}  // namespace view
-
-// what goes in front of the message of an exception about j: nothing for a
-// basic_json value (exception_context() passes the value itself), the context
-// basic_json would add (JSON_DIAGNOSTICS, JSON_DIAGNOSTIC_POSITIONS) for a view
-template<typename BasicJsonType, enable_if_t<is_basic_json<BasicJsonType>::value, int> = 0>
-const char* exception_prefix(const BasicJsonType& /*unused*/) noexcept
-{
-    return "";
-}
-
-template<typename View, enable_if_t<is_json_view<View>::value, int> = 0>
-std::string exception_prefix(const View& v)
-{
-    return view::diagnostics_of(v);
-}
-
 /*!
@brief throws because @a j does not have the type a conversion expects
@param[in] expected  the expected type(s), e.g. "array" or "binary or array"
@@ -5961,7 +5939,7 @@ JSON_HEDLEY_NO_RETURN JSON_HEDLEY_NEVER_INLINE void throw_type_must_be(const cha
 {
    static_cast<void>(expected); // unused when JSON_NOEXCEPTION is defined
    static_cast<void>(j);
-    JSON_THROW(type_error::create(exception_id::type_mismatch, concat(exception_prefix(j), "type must be ", expected, ", but is ", j.type_name()), exception_context(j)));
+    JSON_THROW(type_error::create(exception_id::type_mismatch, concat("type must be ", expected, ", but is ", j.type_name()), exception_context(j)));
 }

 /*!
@@ -15,7 +15,6 @@
 #include <nlohmann/json_view.hpp>

 #include <algorithm> // any_of
-#include <cstddef> // size_t
 #include <functional> // function
 #include <random> // mt19937
 #include <string> // string
@@ -89,26 +88,6 @@ inline bool has_duplicate_keys(const nlohmann::ordered_json_view& v)
    });
 }

-// the message of an exception about the value at path (a JSON pointer, "" for
-// the root) whose source bytes are [start, end): the context basic_json adds
-// with JSON_DIAGNOSTICS and JSON_DIAGNOSTIC_POSITIONS, if enabled, then what
-inline std::string message(const std::string& id, const std::string& path, std::size_t start, std::size_t end, const std::string& what)
-{
-    std::string context;
-#if JSON_DIAGNOSTIC_POSITIONS
-    context = "(bytes " + std::to_string(start) + "-" + std::to_string(end) + ") ";
-#else
-    static_cast<void>(start);
-    static_cast<void>(end);
-#endif
-#if JSON_DIAGNOSTICS
-    context = path.empty() ? "" : "(" + path + ") " + context;
-#else
-    static_cast<void>(path);
-#endif
-    return "[json.exception." + id + "] " + context + what;
-}
-
 #if !defined(JSON_NOEXCEPTION)
 // the exception a call throws, or "" if it throws none
 inline std::string exception_of_call(const std::function<void()>& f)
@@ -225,7 +225,7 @@ TEST_CASE("json_view")
 #if JSON_DIAGNOSTICS
        // the parents are set, so errors name the path
        const json m = materialized<json_document>(R"({"a":{"b":[1]}})");
-        CHECK_THROWS_WITH_AS(m.at("a").at("b").at(0).at("x"), json_view_test::message("type_error.304", "/a/b/0", 11, 12, "cannot use at() with number").c_str(), json::type_error&);
+        CHECK_THROWS_WITH_AS(m.at("a").at("b").at(0).at("x"), "[json.exception.type_error.304] (/a/b/0) cannot use at() with number", json::type_error&);
 #endif
    }

@@ -750,6 +750,19 @@ std::string exception_of(F f)
    return "";
 }

+// the exception a call on a basic_json value throws, without the byte range of
+// the value (JSON_DIAGNOSTIC_POSITIONS), which the exceptions of views lack
+template<typename F>
+std::string json_exception_of(F f)
+{
+    std::string what = exception_of(f);
+    const std::size_t at = what.find("] (bytes ");
+    if (at != std::string::npos)
+    {
+        what.erase(at + 2, what.find(") ", at) - at);
+    }
+    return what;
+}
 #endif

 // compares a view with the ordered_json value materialize() gives for it:
@@ -958,25 +971,24 @@ TEST_CASE("json_view element access and iteration")
 #if !defined(JSON_NOEXCEPTION)
            if (!j.is_object())
            {
-                CHECK(exception_of([&] { static_cast<void>(v["a"]); }) == exception_of([&] { static_cast<void>(j["a"]); }));
+                CHECK(exception_of([&] { static_cast<void>(v["a"]); }) == json_exception_of([&] { static_cast<void>(j["a"]); }));
            }
            if (!j.is_array())
            {
-                CHECK(exception_of([&] { static_cast<void>(v[0]); }) == exception_of([&] { static_cast<void>(j[0]); }));
+                CHECK(exception_of([&] { static_cast<void>(v[0]); }) == json_exception_of([&] { static_cast<void>(j[0]); }));
            }
-            CHECK(exception_of([&] { static_cast<void>(v.at("a")); }) == exception_of([&] { static_cast<void>(j.at("a")); }));
-            CHECK(exception_of([&] { static_cast<void>(v.at("missing")); }) == exception_of([&] { static_cast<void>(j.at("missing")); }));
-            CHECK(exception_of([&] { static_cast<void>(v.at(0)); }) == exception_of([&] { static_cast<void>(j.at(0)); }));
-            CHECK(exception_of([&] { static_cast<void>(v.at(5)); }) == exception_of([&] { static_cast<void>(j.at(5)); }));
+            CHECK(exception_of([&] { static_cast<void>(v.at("a")); }) == json_exception_of([&] { static_cast<void>(j.at("a")); }));
+            CHECK(exception_of([&] { static_cast<void>(v.at("missing")); }) == json_exception_of([&] { static_cast<void>(j.at("missing")); }));
+            CHECK(exception_of([&] { static_cast<void>(v.at(0)); }) == json_exception_of([&] { static_cast<void>(j.at(0)); }));
+            CHECK(exception_of([&] { static_cast<void>(v.at(5)); }) == json_exception_of([&] { static_cast<void>(j.at(5)); }));
            if (!(j.is_object() && j.empty())) // (key() of an end iterator)
            {
-                // (without the context of basic_json: view iterators do not know the value they iterate over)
-                CHECK(exception_of([&] { static_cast<void>(v.begin().key()); }) == (j.is_object() ? "" : "[json.exception.invalid_iterator.207] cannot use key() for non-object iterators"));
+                CHECK(exception_of([&] { static_cast<void>(v.begin().key()); }) == json_exception_of([&] { static_cast<void>(j.begin().key()); }));
            }
            if (!j.empty() || j.is_null())
            {
-                CHECK(exception_of([&] { static_cast<void>(v.front()); }) == exception_of([&] { static_cast<void>(j.front()); }));
-                CHECK(exception_of([&] { static_cast<void>(v.back()); }) == exception_of([&] { static_cast<void>(j.back()); }));
+                CHECK(exception_of([&] { static_cast<void>(v.front()); }) == json_exception_of([&] { static_cast<void>(j.front()); }));
+                CHECK(exception_of([&] { static_cast<void>(v.back()); }) == json_exception_of([&] { static_cast<void>(j.back()); }));
            }
 #endif
            CHECK(v.contains("a") == j.contains("a"));
@@ -988,8 +1000,8 @@ TEST_CASE("json_view element access and iteration")
        const json_document d = json_document::parse(R"({"a":[]})");
        CHECK(d.root()["b"].is_discarded());
        CHECK(d.root()["a"][0].is_discarded());
-        CHECK_THROWS_WITH_AS(d.root()["a"].front(), json_view_test::message("invalid_iterator.214", "/a", 5, 7, "cannot get value").c_str(), json::invalid_iterator&);
-        CHECK_THROWS_WITH_AS(d.root()["a"].back(), json_view_test::message("invalid_iterator.214", "/a", 5, 7, "cannot get value").c_str(), json::invalid_iterator&);
+        CHECK_THROWS_WITH_AS(d.root()["a"].front(), "[json.exception.invalid_iterator.214] cannot get value", json::invalid_iterator&);
+        CHECK_THROWS_WITH_AS(d.root()["a"].back(), "[json.exception.invalid_iterator.214] cannot get value", json::invalid_iterator&);
        const json_view invalid{};
        CHECK(invalid.begin() == invalid.end());
        CHECK(std::string(invalid.type_name()) == "discarded");
@@ -1020,10 +1032,10 @@ TEST_CASE("json_view element access and iteration")
        CHECK(v[json_view::json_pointer("/a/b/5")][0].is_discarded());
 #if !defined(JSON_NOEXCEPTION)
        // type errors on values that are not discarded stay
-        CHECK_THROWS_WITH_AS(v[0], json_view_test::message("type_error.305", "", 0, 29, "cannot use operator[] with a numeric argument with object").c_str(), json::type_error&);
-        CHECK_THROWS_WITH_AS(v["a"]["b"]["c"], json_view_test::message("type_error.305", "/a/b", 10, 17, "cannot use operator[] with a string argument with array").c_str(), json::type_error&);
-        CHECK_THROWS_WITH_AS(v["s"]["c"], json_view_test::message("type_error.305", "/s", 23, 28, "cannot use operator[] with a string argument with string").c_str(), json::type_error&);
-        CHECK_THROWS_WITH_AS(v["s"][0], json_view_test::message("type_error.305", "/s", 23, 28, "cannot use operator[] with a numeric argument with string").c_str(), json::type_error&);
+        CHECK_THROWS_WITH_AS(v[0], "[json.exception.type_error.305] cannot use operator[] with a numeric argument with object", json::type_error&);
+        CHECK_THROWS_WITH_AS(v["a"]["b"]["c"], "[json.exception.type_error.305] cannot use operator[] with a string argument with array", json::type_error&);
+        CHECK_THROWS_WITH_AS(v["s"]["c"], "[json.exception.type_error.305] cannot use operator[] with a string argument with string", json::type_error&);
+        CHECK_THROWS_WITH_AS(v["s"][0], "[json.exception.type_error.305] cannot use operator[] with a numeric argument with string", json::type_error&);
        CHECK_THROWS_AS(v["a"]["b"][0]["c"], json::type_error&);
        CHECK_THROWS_AS(v["s"][json_view::json_pointer("/x")], json::out_of_range&);
        // at() keeps throwing on a discarded view
@@ -1098,9 +1110,9 @@ TEST_CASE("json_view element access and iteration")
        CHECK(v[(std::numeric_limits<std::size_t>::max)()].is_discarded());
        CHECK(v[std::numeric_limits<int>::max()].is_discarded());
 #if !defined(JSON_NOEXCEPTION)
-        CHECK_THROWS_WITH_AS(v.at(3), json_view_test::message("out_of_range.401", "", 0, 10, "array index 3 is out of range").c_str(), json::out_of_range&);
-        CHECK_THROWS_WITH_AS(v.at(3u), json_view_test::message("out_of_range.401", "", 0, 10, "array index 3 is out of range").c_str(), json::out_of_range&);
-        CHECK_THROWS_WITH_AS(v.at(std::int64_t(3)), json_view_test::message("out_of_range.401", "", 0, 10, "array index 3 is out of range").c_str(), json::out_of_range&);
+        CHECK_THROWS_WITH_AS(v.at(3), "[json.exception.out_of_range.401] array index 3 is out of range", json::out_of_range&);
+        CHECK_THROWS_WITH_AS(v.at(3u), "[json.exception.out_of_range.401] array index 3 is out of range", json::out_of_range&);
+        CHECK_THROWS_WITH_AS(v.at(std::int64_t(3)), "[json.exception.out_of_range.401] array index 3 is out of range", json::out_of_range&);
        CHECK_THROWS_AS(v.at(-1), json::out_of_range&);
        CHECK_THROWS_AS(v.at(-1L), json::out_of_range&);
        CHECK_THROWS_AS(v.at(std::int64_t(-1)), json::out_of_range&);
@@ -1234,6 +1246,26 @@ TEST_CASE("json_view element access and iteration")

 namespace
 {
+#if !defined(JSON_NOEXCEPTION)
+// an exception message without the context that basic_json adds with
+// JSON_DIAGNOSTICS ("(/path) ") and JSON_DIAGNOSTIC_POSITIONS ("(bytes 1-2) ");
+// the view's exceptions have no such context
+std::string without_path(std::string msg)
+{
+    for (const char* prefix :
+            {"] (/", "] (bytes "
+            })
+    {
+        const std::size_t open = msg.find(prefix);
+        if (open != std::string::npos)
+        {
+            msg.erase(open + 2, msg.find(") ", open) + 2 - (open + 2));
+        }
+    }
+    return msg;
+}
+#endif
+
 // the bits of a float, to compare values bit for bit
 std::uint64_t bits(double x)
 {
@@ -1304,18 +1336,18 @@ void check_values(const ordered_json_view& v, const ordered_json& j, const std::
    // conversions to the wrong type throw what basic_json throws
    if (!j.is_number())
    {
-        CHECK(exception_of([&] { static_cast<void>(v.get<int>()); }) == exception_of([&] { static_cast<void>(j.get<int>()); }));
+        CHECK(exception_of([&] { static_cast<void>(v.get<int>()); }) == without_path(exception_of([&] { static_cast<void>(j.get<int>()); })));
    }
-    CHECK(exception_of([&] { static_cast<void>(v.get<bool>()); }) == exception_of([&] { static_cast<void>(j.get<bool>()); }));
-    CHECK(exception_of([&] { static_cast<void>(v.get<std::string>()); }) == exception_of([&] { static_cast<void>(j.get<std::string>()); }));
-    CHECK(exception_of([&] { static_cast<void>(v.get<std::nullptr_t>()); }) == exception_of([&] { static_cast<void>(j.get<std::nullptr_t>()); }));
+    CHECK(exception_of([&] { static_cast<void>(v.get<bool>()); }) == without_path(exception_of([&] { static_cast<void>(j.get<bool>()); })));
+    CHECK(exception_of([&] { static_cast<void>(v.get<std::string>()); }) == without_path(exception_of([&] { static_cast<void>(j.get<std::string>()); })));
+    CHECK(exception_of([&] { static_cast<void>(v.get<std::nullptr_t>()); }) == without_path(exception_of([&] { static_cast<void>(j.get<std::nullptr_t>()); })));
    if (!j.is_array())
    {
-        CHECK(exception_of([&] { static_cast<void>(v.get<std::vector<int>>()); }) == exception_of([&] { static_cast<void>(j.get<std::vector<int>>()); }));
+        CHECK(exception_of([&] { static_cast<void>(v.get<std::vector<int>>()); }) == without_path(exception_of([&] { static_cast<void>(j.get<std::vector<int>>()); })));
    }
    if (!j.is_object())
    {
-        CHECK(exception_of([&] { static_cast<void>(v.get<std::map<std::string, int>>()); }) == exception_of([&] { static_cast<void>(j.get<std::map<std::string, int>>()); }));
+        CHECK(exception_of([&] { static_cast<void>(v.get<std::map<std::string, int>>()); }) == without_path(exception_of([&] { static_cast<void>(j.get<std::map<std::string, int>>()); })));
    }
 #endif

@@ -1458,8 +1490,8 @@ TEST_CASE("json_view values")
        CHECK(v[3].number_token() == "123456789012345678901234567890");
        CHECK(v[4].number_token() == "-12");
        CHECK(v[5].number_token() == "7");
-        CHECK_THROWS_WITH_AS(v[6].number_token(), json_view_test::message("type_error.302", "/6", 56, 59, "type must be number, but is string").c_str(), json::type_error&);
-        CHECK_THROWS_WITH_AS(v.get_string(), json_view_test::message("type_error.302", "", 0, 60, "type must be string, but is array").c_str(), json::type_error&);
+        CHECK_THROWS_WITH_AS(v[6].number_token(), "[json.exception.type_error.302] type must be number, but is string", json::type_error&);
+        CHECK_THROWS_WITH_AS(v.get_string(), "[json.exception.type_error.302] type must be string, but is array", json::type_error&);
    }

    SECTION("conversions")
@@ -1533,15 +1565,15 @@ TEST_CASE("json_view values")
        CHECK(v["o"]["x"].value(json::json_pointer("/1"), 0) == j["o"]["x"].value(json::json_pointer("/1"), 0));
        CHECK(v["o"]["x"].value(json::json_pointer("/7"), 3) == j["o"]["x"].value(json::json_pointer("/7"), 3));
 #if !defined(JSON_NOEXCEPTION)
-        CHECK(exception_of([&] { static_cast<void>(v["o"]["x"].value("k", 0)); }) == exception_of([&] { static_cast<void>(j["o"]["x"].value("k", 0)); }));
-        CHECK(exception_of([&] { static_cast<void>(v.value("s", 0)); }) == exception_of([&] { static_cast<void>(j.value("s", 0)); }));
-        CHECK(exception_of([&] { static_cast<void>(v["n"].value("x", 0)); }) == exception_of([&] { static_cast<void>(j["n"].value("x", 0)); }));
-        CHECK(exception_of([&] { static_cast<void>(v["n"].value(json::json_pointer("/x"), 0)); }) == exception_of([&] { static_cast<void>(j["n"].value(json::json_pointer("/x"), 0)); }));
+        CHECK(exception_of([&] { static_cast<void>(v["o"]["x"].value("k", 0)); }) == without_path(exception_of([&] { static_cast<void>(j["o"]["x"].value("k", 0)); })));
+        CHECK(exception_of([&] { static_cast<void>(v.value("s", 0)); }) == without_path(exception_of([&] { static_cast<void>(j.value("s", 0)); })));
+        CHECK(exception_of([&] { static_cast<void>(v["n"].value("x", 0)); }) == without_path(exception_of([&] { static_cast<void>(j["n"].value("x", 0)); })));
+        CHECK(exception_of([&] { static_cast<void>(v["n"].value(json::json_pointer("/x"), 0)); }) == without_path(exception_of([&] { static_cast<void>(j["n"].value(json::json_pointer("/x"), 0)); })));
        // string defaults: the member is not a string, or the value is neither an object nor an array
-        CHECK(exception_of([&] { static_cast<void>(v.value("n", "default")); }) == exception_of([&] { static_cast<void>(j.value("n", "default")); }));
-        CHECK(exception_of([&] { static_cast<void>(v["n"].value("x", "default")); }) == exception_of([&] { static_cast<void>(j["n"].value("x", "default")); }));
-        CHECK(exception_of([&] { static_cast<void>(v.value(json::json_pointer("/n"), "default")); }) == exception_of([&] { static_cast<void>(j.value(json::json_pointer("/n"), "default")); }));
-        CHECK(exception_of([&] { static_cast<void>(v["s"].value(json::json_pointer("/x"), "default")); }) == exception_of([&] { static_cast<void>(j["s"].value(json::json_pointer("/x"), "default")); }));
+        CHECK(exception_of([&] { static_cast<void>(v.value("n", "default")); }) == without_path(exception_of([&] { static_cast<void>(j.value("n", "default")); })));
+        CHECK(exception_of([&] { static_cast<void>(v["n"].value("x", "default")); }) == without_path(exception_of([&] { static_cast<void>(j["n"].value("x", "default")); })));
+        CHECK(exception_of([&] { static_cast<void>(v.value(json::json_pointer("/n"), "default")); }) == without_path(exception_of([&] { static_cast<void>(j.value(json::json_pointer("/n"), "default")); })));
+        CHECK(exception_of([&] { static_cast<void>(v["s"].value(json::json_pointer("/x"), "default")); }) == without_path(exception_of([&] { static_cast<void>(j["s"].value(json::json_pointer("/x"), "default")); })));
 #endif
        // (defaults and members longer than the short string optimization)
        CHECK(v.value("s", "a default longer than fifteen characters") == "text");
@@ -1600,7 +1632,7 @@ TEST_CASE("json_view JSON pointers")
        {
            CAPTURE(pointer)
            const json::json_pointer p(pointer);
-            const std::string at_error = exception_of([&] { static_cast<void>(j.at(p)); });
+            const std::string at_error = without_path(exception_of([&] { static_cast<void>(j.at(p)); }));
            CHECK(exception_of([&] { static_cast<void>(v.at(p)); }) == at_error);
            if (at_error.empty())
            {
@@ -1614,7 +1646,7 @@ TEST_CASE("json_view JSON pointers")
            }
            else
            {
-                CHECK(exception_of([&] { static_cast<void>(v[p]); }) == exception_of([&] { static_cast<void>(j[p]); }));
+                CHECK(exception_of([&] { static_cast<void>(v[p]); }) == without_path(exception_of([&] { static_cast<void>(j[p]); })));
            }
            // (basic_json::contains() throws out_of_range.404 for an empty
            // array index token, although it is not meant to throw; the view
@@ -1625,7 +1657,7 @@ TEST_CASE("json_view JSON pointers")
                static_cast<void>(found);
            });
            CHECK(v.contains(p) == (contains_error.empty() && j.contains(p)));
-            CHECK(exception_of([&] { static_cast<void>(v.value(p, 5)); }) == exception_of([&] { static_cast<void>(j.value(p, 5)); }));
+            CHECK(exception_of([&] { static_cast<void>(v.value(p, 5)); }) == without_path(exception_of([&] { static_cast<void>(j.value(p, 5)); })));
        }
    }
 #endif
@@ -59,7 +59,8 @@ built build(const std::string& text, bool comments, bool trailing_commas, bool s
        r.copy.assign(text.begin(), text.end());
        src = r.copy.data();
    }
-    r.ok = nlohmann::detail::view::build < FloatType, !nlohmann::detail::abi_config::strict_nul_handling > (*r.data, src, text.size(), comments, trailing_commas, sentinel, r.failure);
+    constexpr bool nul_is_end = !nlohmann::detail::abi_config::strict_nul_handling;
+    r.ok = nlohmann::detail::view::build<FloatType, nul_is_end>(*r.data, src, text.size(), comments, trailing_commas, sentinel, false, r.failure);
    r.data->src = src;
    r.data->base[0] = src;
    r.data->base[1] = r.data->arena.data();
@@ -172,6 +173,22 @@ void check_string(const std::string& content)
    }
 }

+// accept() stores no nodes: it must accept and reject what json::accept does, for all options and for inputs with
+// and without a terminating NUL
+void check_accept(const std::string& text)
+{
+    CAPTURE(text)
+    const std::vector<char> bytes(text.begin(), text.end());
+    for (int options = 0; options < 4; ++options)
+    {
+        const bool comments = (options & 1) != 0;
+        const bool trailing_commas = (options & 2) != 0;
+        const bool accepted = json::accept(text, comments, trailing_commas);
+        CHECK(nlohmann::json_document::accept(text, comments, trailing_commas) == accepted);
+        CHECK(nlohmann::json_document::accept(bytes, comments, trailing_commas) == accepted);
+    }
+}
+
 // a small deterministic generator of documents
 struct generator
 {
@@ -423,6 +440,133 @@ TEST_CASE("json_view builder")
        }
    }

+    SECTION("accept() without an index")
+    {
+        for (const char* text :
+                {
+                    "", " ", "\n", "null", "nul", "true", "[", "]", "[]", "{}", "[1,2,3]", "[1,2,3", "[1,2,3,]", "{\"a\":1,}", "{\"a\"}", "{\"a\":}",
+                    "[1] x", "[1][2]", "\xEF\xBB\xBF[1]", "[\"a\\", "[\"\\u12\"]", "[\"\\ud800\"]", "[\"\x01\"]", "[\"\xff\"]", "[01]", "[1.]",
+                    "[.5]", "[-]", "[1e]", "// c\n[1]", "/* c */ {\"a\" /* x */ : 1}", "/* c", "[1] // c", "1e400", "-1e400", "123456789012345678901234567890",
+                    "{\"a\":1,\"a\":2}", "[[[]]]", "\"\\u00e4\\n\\ud83d\\ude00\""
+                })
+        {
+            check_accept(text);
+        }
+        // a null byte inside the text, and after it
+        check_accept(std::string("[1,\0]", 5));
+        check_accept(std::string("[1]\0", 4));
+        check_accept(std::string("\0", 1));
+
+        // generated documents and damaged copies, as for the builder above
+        generator g;
+        for (int i = 0; i < 2000; ++i)
+        {
+            std::string text;
+            g.value(text, 0);
+            check_accept(text);
+            std::string damaged = text;
+            const auto at = static_cast<std::size_t>(g.r(static_cast<int>(damaged.size())));
+            static const char replacements[] = {'x', '"', '\\', ',', ':', ']', '}', '[', '{', '1', '-', '.', 'e', '\0', '\n', '/'}; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
+            damaged[at] = replacements[g.r(16)];
+            check_accept(damaged);
+            check_accept(text.substr(0, at));
+        }
+
+        // nesting beyond the 64 levels that are kept on the builder's own stack, closed and not closed
+        for (const std::size_t depth :
+                {
+                    63, 64, 65, 66, 200, 1000
+                })
+        {
+            check_accept(std::string(depth, '[') + std::string(depth, ']'));
+            check_accept(std::string(depth, '[') + std::string(depth - 1, ']'));
+            std::string objects;
+            for (std::size_t i = 0; i < depth; ++i)
+            {
+                objects += "{\"k\":";
+            }
+            objects += "1" + std::string(depth, '}');
+            check_accept(objects);
+            check_accept(objects.substr(0, objects.size() - 1));
+        }
+
+        // objects with enough members to get a hash index when they are indexed (and duplicate keys)
+        std::string large = "{";
+        for (int i = 0; i < 300; ++i)
+        {
+            large += (i == 0 ? "\"k" : ",\"k") + std::to_string(i % 200) + "\":" + std::to_string(i);
+        }
+        check_accept(large + "}");
+        check_accept(large);
+        check_accept("[" + large + "},{" + large.substr(1) + "}]");
+
+        // the overflow check uses the floating-point type of the document
+        using float_json = nlohmann::basic_json<std::map, std::vector, std::string, bool, std::int64_t, std::uint64_t, float>;
+        for (const char* text :
+                {
+                    "1e39", "-1e39", "3.4028235e38", "3.4028236e38", "[1.5e38, 3.5e38]", "{\"a\": 1e-50, \"b\": 1e39}", "340282356779733661637539395458142568448"
+                })
+        {
+            CAPTURE(text)
+            CHECK(nlohmann::basic_json_document<float_json>::accept(text) == float_json::accept(text));
+        }
+
+        // strings are checked and not decoded: runs of text of every length from 0 to 40 between valid and invalid
+        // escapes, UTF-8 sequences and control characters, in values and in keys, cut near the end of the text
+        const std::array<const char*, 9> valid = {{"\\n", "\\\"", "\\\\", "\\/", "\\t", "\\u00e4", "\\u20ac", "\\ud83d\\ude00", "\\u0000"}};
+        const std::array<const char*, 12> invalid = {{"\\x", "\\ud800", "\\udc00", "\\u12G4", "\\u12", "\\ud83dx", "\\ud83d\\u0041", "\\ud83d\\ud83d", "\\", "\x01", "\x1f", "\x7f"}};
+        const std::array<const char*, 6> utf8 = {{"\xc3\xa4", "\xe2\x82\xac", "\xf0\x9f\x98\x80", "\xc3", "\xff", "\x80"}};
+        std::mt19937 rng(2029); // NOLINT(cert-msc32-c,cert-msc51-cpp,bugprone-random-generator-seed): reproducible
+        for (std::size_t run = 0; run <= 40; ++run)
+        {
+            for (int i = 0; i < 30; ++i)
+            {
+                std::string content = std::string(rng() % 20, 'a');
+                const auto pieces = 1 + (rng() % 6);
+                for (unsigned k = 0; k < pieces; ++k)
+                {
+                    content += valid[rng() % valid.size()];
+                    content += std::string(k == 0 ? run : rng() % 41, static_cast<char>('b' + (rng() % 20)));
+                    switch (rng() % 8)
+                    {
+                        case 0:
+                            content += utf8[rng() % 3];
+                            break;
+                        case 1:
+                            content += utf8[rng() % utf8.size()];
+                            break;
+                        case 2:
+                            content += invalid[rng() % invalid.size()];
+                            break;
+                        default:
+                            break;
+                    }
+                }
+                for (const std::string& text :
+                        {
+                            "[\"" + content + "\"]", "{\"" + content + "\":1}", "[\"" + content, "[\"" + content.substr(0, content.size() - (rng() % 4)) + "\"]"
+                        })
+                {
+                    check_accept(text);
+                }
+            }
+        }
+    }
+
+    SECTION("escapes in a row")
+    {
+        for (const char* content :
+                {
+                    "\\n", "\\n\\t\\\\", "\\u00e9\\u00e9\\u4e2d", "\\u00e9\\u00e", "\\u00e9\\", "\\n\\q", "\\n\\ud83d\\ude00\\n",
+                    "\\ud83d\\ude00\\ud83d", "\\n\\n\\n abc \\n\\n", "\\n\x01", "\\n\xC3\x28", "\\n\\"
+                })
+        {
+            check_accept(std::string("[\"") + content + "\"]");
+            check_accept(std::string("[\"") + content);
+            check_accept(std::string("{\"") + content + "\":1}");
+        }
+    }
+
    SECTION("test files")
    {
        for (const char* name :
@@ -462,7 +462,7 @@ TEST_CASE("json_view large objects")
        CHECK(v[""].get_string() == "empty key");
        CHECK(v["k1"].get<int>() == 1); // the first of duplicate keys, as for small objects
        CHECK(!v.contains("missing"));
-        CHECK_THROWS_WITH_AS(v.at("missing"), json_view_test::message("out_of_range.403", "", 0, text.size(), "key 'missing' not found").c_str(), json::out_of_range&);
+        CHECK_THROWS_WITH_AS(v.at("missing"), "[json.exception.out_of_range.403] key 'missing' not found", json::out_of_range&);
        CHECK(v == j);
        CHECK(v.materialize() == j);
    }
@@ -532,18 +532,18 @@ TEST_CASE("json_view edits: errors")

    CHECK_THROWS_WITH_AS(d.set(other_editable.root(), 1), "[json.exception.invalid_iterator.202] view does not belong to this document", json::invalid_iterator&);
    CHECK_THROWS_WITH_AS(d.set(json_editable_view(), 1), "[json.exception.invalid_iterator.202] view does not belong to this document", json::invalid_iterator&);
-    CHECK_THROWS_WITH_AS(d.set(root["a"], "k", 1), json_view_test::message("type_error.305", "/a", 21, 27, "cannot use operator[] with a string argument with array").c_str(), json::type_error&);
-    CHECK_THROWS_WITH_AS(d.set(root["o"], 0, 1), json_view_test::message("type_error.305", "/o", 6, 14, "cannot use operator[] with a numeric argument with object").c_str(), json::type_error&);
-    CHECK_THROWS_WITH_AS(d.set(root["a"], 2, 1), json_view_test::message("out_of_range.401", "/a", 21, 27, "array index 2 is out of range").c_str(), json::out_of_range&);
-    CHECK_THROWS_WITH_AS(d.set(root["a"], -1, 1), json_view_test::message("out_of_range.401", "/a", 21, 27, "array index -1 is out of range").c_str(), json::out_of_range&);
-    CHECK_THROWS_WITH_AS(d.push_back(root["o"], 1), json_view_test::message("type_error.308", "/o", 6, 14, "cannot use push_back() with object").c_str(), json::type_error&);
-    CHECK_THROWS_WITH_AS(d.insert(root["n"], 0, 1), json_view_test::message("type_error.309", "/n", 34, 35, "cannot use insert() with number").c_str(), json::type_error&);
-    CHECK_THROWS_WITH_AS(d.insert(root["a"], 3, 1), json_view_test::message("out_of_range.401", "/a", 21, 27, "array index 3 is out of range").c_str(), json::out_of_range&);
-    CHECK_THROWS_WITH_AS(d.erase(root["n"], "k"), json_view_test::message("type_error.307", "/n", 34, 35, "cannot use erase() with number").c_str(), json::type_error&);
-    CHECK_THROWS_WITH_AS(d.erase(root["o"], 0), json_view_test::message("type_error.307", "/o", 6, 14, "cannot use erase() with object").c_str(), json::type_error&);
-    CHECK_THROWS_WITH_AS(d.erase(root["a"], 2), json_view_test::message("out_of_range.401", "/a", 21, 27, "array index 2 is out of range").c_str(), json::out_of_range&);
+    CHECK_THROWS_WITH_AS(d.set(root["a"], "k", 1), "[json.exception.type_error.305] cannot use operator[] with a string argument with array", json::type_error&);
+    CHECK_THROWS_WITH_AS(d.set(root["o"], 0, 1), "[json.exception.type_error.305] cannot use operator[] with a numeric argument with object", json::type_error&);
+    CHECK_THROWS_WITH_AS(d.set(root["a"], 2, 1), "[json.exception.out_of_range.401] array index 2 is out of range", json::out_of_range&);
+    CHECK_THROWS_WITH_AS(d.set(root["a"], -1, 1), "[json.exception.out_of_range.401] array index -1 is out of range", json::out_of_range&);
+    CHECK_THROWS_WITH_AS(d.push_back(root["o"], 1), "[json.exception.type_error.308] cannot use push_back() with object", json::type_error&);
+    CHECK_THROWS_WITH_AS(d.insert(root["n"], 0, 1), "[json.exception.type_error.309] cannot use insert() with number", json::type_error&);
+    CHECK_THROWS_WITH_AS(d.insert(root["a"], 3, 1), "[json.exception.out_of_range.401] array index 3 is out of range", json::out_of_range&);
+    CHECK_THROWS_WITH_AS(d.erase(root["n"], "k"), "[json.exception.type_error.307] cannot use erase() with number", json::type_error&);
+    CHECK_THROWS_WITH_AS(d.erase(root["o"], 0), "[json.exception.type_error.307] cannot use erase() with object", json::type_error&);
+    CHECK_THROWS_WITH_AS(d.erase(root["a"], 2), "[json.exception.out_of_range.401] array index 2 is out of range", json::out_of_range&);
    CHECK_THROWS_WITH_AS(d.erase(json::json_pointer("")), "[json.exception.out_of_range.405] JSON pointer has no parent", json::out_of_range&);
-    CHECK_THROWS_WITH_AS(d.erase(json::json_pointer("/missing/x")), json_view_test::message("out_of_range.403", "", 0, 47, "key 'missing' not found").c_str(), json::out_of_range&);
+    CHECK_THROWS_WITH_AS(d.erase(json::json_pointer("/missing/x")), "[json.exception.out_of_range.403] key 'missing' not found", json::out_of_range&);
    CHECK_THROWS_WITH_AS(d.set(json::json_pointer("/a/01"), 1), "[json.exception.parse_error.106] parse error: array index '01' must not begin with '0'", json::parse_error&);
    CHECK_THROWS_WITH_AS(d.set(root, json_editable_view()), "[json.exception.type_error.302] type must be a value, but is discarded", json::type_error&);
    CHECK_THROWS_WITH_AS(d.set(root, json::binary({1, 2})), "[json.exception.type_error.319] cannot store a binary value in a json_document", json::type_error&);
@@ -337,7 +337,8 @@ TEST_CASE("json_view from_json")
        CHECK(d.root().get<std::unordered_map<std::string, int>>().at("a") == 3);
    }

-#if !defined(JSON_NOEXCEPTION)
+    // (the exceptions of views have neither the path nor the byte range of the value)
+#if !defined(JSON_NOEXCEPTION) && !JSON_DIAGNOSTICS && !JSON_DIAGNOSTIC_POSITIONS
    SECTION("std types: the same errors as from the materialized value")
    {
        const json_document d = json_document::parse(R"([[1, "x"], {"a": 1}, "text", [1], 5, null])");
@@ -402,10 +403,10 @@ TEST_CASE("json_view from_json")
        CHECK(d.root()[4].get<strict_color>() == strict_color::red);
 #if !defined(JSON_NOEXCEPTION)
        const json j = d.root().materialize();
-#if !JSON_DIAGNOSTICS && !JSON_DIAGNOSTIC_POSITIONS
        CHECK(exception_of_call([&] { static_cast<void>(d.root()[2].get<strict_color>()); }) == "[json.exception.out_of_range.410] enum value out of range for strict_color: \"purple\"");
-#endif
+#if !JSON_DIAGNOSTICS && !JSON_DIAGNOSTIC_POSITIONS
        CHECK(exception_of_call([&] { static_cast<void>(d.root()[2].get<strict_color>()); }) == exception_of_call([&] { static_cast<void>(j[2].get<strict_color>()); }));
+#endif
 #endif
    }

@@ -451,9 +452,11 @@ TEST_CASE("json_view from_json")
        CHECK(o.root().get<shape>().center.y == 2);
    }

-#if !defined(JSON_NOEXCEPTION)
+#if !defined(JSON_NOEXCEPTION) && !JSON_DIAGNOSTICS && !JSON_DIAGNOSTIC_POSITIONS
    SECTION("errors are those of the same conversion of a json value")
    {
+        // (with JSON_DIAGNOSTICS, those of json name the path of the value,
+        // and with JSON_DIAGNOSTIC_POSITIONS its bytes)
        const json_document d = json_document::parse(R"([{"x": 1}, {"x": "1", "y": 2}, [1, 2], {"id": "7", "c": "red"}])");
        const json j = d.root().materialize();
        for (std::size_t i = 0; i < 3; ++i)
@@ -81,112 +81,6 @@ std::string range(const json& j)
 {
    return j.start_pos() == npos && j.end_pos() == npos ? "none" : std::to_string(j.start_pos()) + "-" + std::to_string(j.end_pos());
 }
-
-#if !defined(JSON_NOEXCEPTION)
-using json_view_test::exception_of_call;
-
-// the exceptions about every value of v are those about the value at the same
-// place in j, a value of the whole document from parse() or materialize() (so
-// that its parents and positions are set); members whose key repeats are
-// skipped (the view finds the first one, j holds the last)
-template<typename View>
-void check_exceptions(const View& v, const json& j)
-{
-    CAPTURE(j.dump())
-    if (!v.is_number())
-    {
-        CHECK(exception_of_call([&] { static_cast<void>(v.template get<int>()); }) == exception_of_call([&] { static_cast<void>(j.get<int>()); }));
-    }
-    if (!v.is_string())
-    {
-        CHECK(exception_of_call([&] { static_cast<void>(v.template get<std::string>()); }) == exception_of_call([&] { static_cast<void>(j.get<std::string>()); }));
-    }
-    if (!v.is_array())
-    {
-        CHECK(exception_of_call([&] { static_cast<void>(v.template get<std::vector<int>>()); }) == exception_of_call([&] { static_cast<void>(j.get<std::vector<int>>()); }));
-    }
-    CHECK(exception_of_call([&] { static_cast<void>(v.at("missing")); }) == exception_of_call([&] { static_cast<void>(j.at("missing")); }));
-    CHECK(exception_of_call([&] { static_cast<void>(v.at(1000)); }) == exception_of_call([&] { static_cast<void>(j.at(1000)); }));
-    CHECK(exception_of_call([&] { static_cast<void>(v.at(json::json_pointer("/missing"))); }) == exception_of_call([&] { static_cast<void>(j.at(json::json_pointer("/missing"))); }));
-    CHECK(exception_of_call([&] { static_cast<void>(v.at(json::json_pointer("/-"))); }) == exception_of_call([&] { static_cast<void>(j.at(json::json_pointer("/-"))); }));
-    CHECK(exception_of_call([&] { static_cast<void>(v.value("k", 0)); }) == exception_of_call([&] { static_cast<void>(j.value("k", 0)); }));
-    if (!v.is_object())
-    {
-        CHECK(exception_of_call([&] { static_cast<void>(v["k"]); }) == exception_of_call([&] { static_cast<void>(j["k"]); }));
-        // (without the context of basic_json: view iterators do not know the value they iterate over)
-        CHECK(exception_of_call([&] { static_cast<void>(v.begin().key()); }) == "[json.exception.invalid_iterator.207] cannot use key() for non-object iterators");
-    }
-    if (!v.is_array())
-    {
-        CHECK(exception_of_call([&] { static_cast<void>(v[0]); }) == exception_of_call([&] { static_cast<void>(j[0]); }));
-    }
-    if (v.is_null())
-    {
-        CHECK(exception_of_call([&] { static_cast<void>(v.front()); }) == exception_of_call([&] { static_cast<void>(j.front()); }));
-    }
-    if (v.is_object())
-    {
-        for (auto it = v.begin(); it != v.end(); ++it)
-        {
-            const std::string key(it.key().data(), it.key().size());
-            if (v.count(key) == 1)
-            {
-                check_exceptions(it.value(), j.at(key));
-            }
-        }
-    }
-    else if (v.is_array())
-    {
-        for (std::size_t i = 0; i < v.size(); ++i)
-        {
-            check_exceptions(v[i], j[i]);
-        }
-    }
-}
-
-// as check_exceptions, for edits that fail (they change neither d nor j)
-void check_edit_exceptions(json_editable_document& d, const json_editable_document::view_type& v, json& j)
-{
-    CAPTURE(j.dump())
-    if (!v.is_object() && !v.is_null())
-    {
-        CHECK(exception_of_call([&] { d.set(v, "k", 1); }) == exception_of_call([&] { j["k"] = 1; }));
-        CHECK(exception_of_call([&] { d.erase(v, "k"); }) == exception_of_call([&] { j.erase("k"); }));
-    }
-    if (!v.is_array() && !v.is_null())
-    {
-        CHECK(exception_of_call([&] { d.set(v, 0, 1); }) == exception_of_call([&] { j[0] = 1; }));
-        CHECK(exception_of_call([&] { d.push_back(v, 1); }) == exception_of_call([&] { j.push_back(1); }));
-    }
-    if (!v.is_array())
-    {
-        CHECK(exception_of_call([&] { d.insert(v, 0, 1); }) == exception_of_call([&] { j.insert(j.cbegin(), 1); }));
-        CHECK(exception_of_call([&] { d.erase(v, 0); }) == exception_of_call([&] { j.erase(0); }));
-    }
-    else
-    {
-        CHECK(exception_of_call([&] { d.erase(v, 1000); }) == exception_of_call([&] { j.erase(1000); }));
-    }
-    if (v.is_object())
-    {
-        for (auto it = v.begin(); it != v.end(); ++it)
-        {
-            const std::string key(it.key().data(), it.key().size());
-            if (v.count(key) == 1)
-            {
-                check_edit_exceptions(d, it.value(), j.at(key));
-            }
-        }
-    }
-    else if (v.is_array())
-    {
-        for (std::size_t i = 0; i < v.size(); ++i)
-        {
-            check_edit_exceptions(d, v[i], j[i]);
-        }
-    }
-}
-#endif
 } // namespace

 TEST_CASE("json_view materialize() source positions")
@@ -451,123 +345,3 @@ TEST_CASE("json_view materialize() source positions")
    }
 #endif
 }
-
-#if !defined(JSON_NOEXCEPTION)
-TEST_CASE("json_view exceptions name the path and the bytes of the value")
-{
-    SECTION("as those of basic_json")
-    {
-        const std::vector<std::string> texts =
-        {
-            "null", "true", "42", "\"s\"", "[]", "{}", "[1, [2, [3, []]]]", R"({"a": {"b": [1, {"c": null}]}, "d": "e"})",
-            R"({"a/b": {"~": [1]}, "\u0041\n": {"x": "\t"}, "": [{}]})",
-            R"([1 /* ] */, {"a": [] // }
-, "b": {} } , ])",
-            "\n\t[\r\n  1 ,\n  {\n    \"a\" : [ ]\n  }\n]\n",
-        };
-        for (const auto& text : texts)
-        {
-            CAPTURE(text)
-            const json j = json::parse(text, nullptr, true, true, true);
-            const json_document d = json_document::parse(text, true, true, true);
-            check_exceptions(d.root(), j);
-            json_editable_document e = json_editable_document::parse(text, true, true, true);
-            check_exceptions(e.root(), j);
-            json m = e.root().materialize();
-            check_edit_exceptions(e, e.root(), m);
-        }
-    }
-
-    SECTION("generated documents")
-    {
-        json_view_test::generator gen;
-        for (int i = 0; i < 100; ++i)
-        {
-            std::string text;
-            gen.value(text, 0);
-            CAPTURE(text)
-            const json_document d = json_document::parse(text);
-            check_exceptions(d.root(), json::parse(text));
-        }
-    }
-
-    SECTION("edited documents: as those of materialize()")
-    {
-        const std::string text = R"({"a": [1, 2], "b": {"c": "\n", "d": true}, "e": [3, [4]], "f": "x"})";
-        json_editable_document d = json_editable_document::parse(text);
-        d.set(d.root()["f"], 5);
-        d.push_back(d.root()["a"], json::parse(R"({"n": [null]})"));
-        d.erase(d.root()["e"], 0);
-        d.set(d.root()["b"], "c2", d.root()["e"]);
-        d.insert(d.root()["e"], 0, "new");
-        json m = d.root().materialize();
-        check_exceptions(d.root(), m);
-        check_edit_exceptions(d, d.root(), m);
-        // (a value inside a new container: a path, but no bytes)
-        std::string expected = "[json.exception.type_error.302] ";
-#if JSON_DIAGNOSTICS
-        expected += "(/a/2/n/0) ";
-#endif
-        expected += "type must be number, but is null";
-        CHECK(exception_of_call([&] { static_cast<void>(d.root()["a"][2]["n"][0].get<int>()); }) == expected);
-    }
-
-    SECTION("deep documents with siblings after every nested container")
-    {
-        // the search for the path pushes and pops one frame per level (the
-        // stack reallocates while it grows, and shrinks again at every
-        // sibling): run under a sanitizer, a reference to a popped or moved
-        // frame would show here
-        std::string text = "7";
-        for (int level = 0; level < 40; ++level)
-        {
-            text = R"([[1, [2]], )" + text + R"(, {"k": [3, {"l": [4]}]}, [5, [6, [7]]]])";
-        }
-        CAPTURE(text)
-        const json j = json::parse(text);
-        const json_document d = json_document::parse(text);
-        check_exceptions(d.root(), j);
-        json_editable_document e = json_editable_document::parse(text);
-        e.set(e.root()[0][0], 9);
-        check_exceptions(e.root(), e.root().materialize());
-    }
-
-    SECTION("examples")
-    {
-        const std::string text = R"({"people": [{"name": "a", "age": 1}, {"name": "c", "age": "x"}], "o": {"k": 1}})";
-        const json_document d = json_document::parse(text);
-        std::string expected_age = "[json.exception.type_error.302] ";
-#if JSON_DIAGNOSTICS
-        expected_age += "(/people/1/age) ";
-#endif
-        expected_age += "(bytes 58-61) type must be number, but is string";
-        CHECK(exception_of_call([&] { static_cast<void>(d.root()["people"][1]["age"].get<int>()); }) == expected_age);
-
-        std::string expected_zz = "[json.exception.out_of_range.403] ";
-#if JSON_DIAGNOSTICS
-        expected_zz += "(/people/0) ";
-#endif
-        expected_zz += "(bytes 12-35) key 'zz' not found";
-        CHECK(exception_of_call([&] { static_cast<void>(d.root().at(json::json_pointer("/people/0/zz"))); }) == expected_zz);
-
-        // the root has no path, and with JSON_DIAGNOSTICS then no bytes either (as basic_json)
-        std::string expected_missing = "[json.exception.out_of_range.403] ";
-#if !JSON_DIAGNOSTICS
-        expected_missing += "(bytes 0-79) ";
-#endif
-        expected_missing += "key 'missing' not found";
-        CHECK(exception_of_call([&] { static_cast<void>(d.root().at("missing")); }) == expected_missing);
-    }
-
-    SECTION("duplicate keys: the value the view finds")
-    {
-        const json_document d = json_document::parse(R"({"x": "1", "x": "22"})");
-        std::string expected = "[json.exception.type_error.302] ";
-#if JSON_DIAGNOSTICS
-        expected += "(/x) ";
-#endif
-        expected += "(bytes 6-9) type must be number, but is string";
-        CHECK(exception_of_call([&] { static_cast<void>(d.root()["x"].get<int>()); }) == expected);
-    }
-}
-#endif
Author	SHA1	Message	Date
Niels Lohmann	7004ec71bb	json_view: keep accept()'s string check out of run() Clang 23 made run() slower on files without escapes (mesh.pretty +15 %) when the check-only string path was a separate call target. Dispatch inside slow_string() instead, so the call in run() is the same as before, and skip the SIMD run scan between escapes that follow each other (twitterescaped 1.11 -> 0.82 against the previous commit). Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-31 11:14:52 +01:00
Niels Lohmann	6b42cfd1c9	tests: avoid astyle-mangled build<> call in json_view builder test astyle pads the template argument list of the build<...>() call with spaces because the second argument is a negated expression. Name the constant first (as json_view.hpp does with nul_is_end) so astyle leaves the call alone. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-31 11:14:51 +01:00
Niels Lohmann	83322fe0ad	json_view: pass accept()'s validate-only request as a parameter Address review of #5970: - build() takes validate_only as an argument; the validate_only members of document_data and basic_json_document are removed, so neither grows - the internal read path takes an on_error mode (discard, raise, validate) instead of allow_exceptions; accept() calls it with on_error::validate - build_with() has no default for Store - drop the unneeded static_casts in push_node() - name the NulIsEnd argument so astyle keeps build<...> intact - explain in the docs and code why comments/trailing commas keep the index Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-31 11:14:50 +01:00
Niels Lohmann	9ba25b1b66	json_view: accept() checks strings without decoding them The builder that accept() runs stores no nodes, but still decoded every string with escapes into the arena (slow_string(): memcpy of the runs between escapes and the UTF-8 of every \u escape). It now calls check_string() instead, which has the same checks and the same errors and error positions (control characters, ill-formed UTF-8, bad escapes, bad hex digits, lone and unpaired surrogates, a missing closing quote) and skips the text between them with scan_string_run(), without writing anything. The builder that stores keeps slow_string(). The flag that passes the request from accept() to build() now sits next to `discarded` in document_data, where it uses padding: no member of document_data moves (the first version put it after `nodes`, which moved all members behind it by eight bytes). Tests: the new section of the accept test checks runs of text of every length from 0 to 40 between valid and invalid escapes, UTF-8 sequences and control characters, in values and in keys, cut near the end of the text, against json::accept(). Checked against a checker that accepts a lone low surrogate. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-30 22:34:32 +01:00
Niels Lohmann	dea2a4434a	json_view: accept() checks the text without writing an index json_document::accept() ran the builder that writes the node index and discarded the index. For input without comments and trailing commas it now runs a second instantiation of the builder, with a template parameter Store that is false: the grammar, number, string, UTF-8 and nesting checks are the same code, but no node is written, the container nodes are not patched when they close, the node array is not reserved, and no list of large objects is kept. What only builds the arguments of a node (integer conversion, the digit counts of floats) is not run either. accept() with comments or trailing commas and parse() are not changed; the builder that stores is the one parse() always used. A flag of the document passes the request from accept() to build(). accept() on twitter, citm_catalog, canada and the two minified files, A/B in one binary, 6 code layouts, time after / before (geometric mean of the five; the other 14 files of the set are faster too, none is slower): - Apple M1 Max, Apple clang 21: 0.89 - x86-64 Haswell, GCC 16.2: 0.75 - x86-64 Haswell, Clang 23: 0.78 (semanticscholar-corpus.json: 0.52 on both x86 compilers.) parse() runs the same instructions as before; its timings moved by up to 3 % on a few small files with unchanged instruction counts (code placement). Tests: accept() against json::accept() for the same inputs with all four option combinations and with and without a terminating NUL: 2,000 generated documents and damaged copies of them, nesting from 63 to 1000 levels (closed and not), objects with 300 members, a null byte in the text, and float overflow for a float document. Checked against a deliberately broken validator. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-30 22:18:14 +01:00