Niels Lohmann
63c10a51fc
* Review and extend the documentation, and check it in CI A review of all documentation pages found factual errors, dead links, missing cross-references, and gaps in examples. This fixes them and adds checks so the same problems are caught automatically. Fixes: - wrong signatures and version histories (operator!= C++20 member, binary() subtype type, get<PointerType>(), JSON_NO_THREAD_LOCAL, ...) - stale descriptions (number parsing since #5283, UBJSON table, SAX example that no longer compiled, tsl::ordered_map advice) - dead internal and external links; repology.org badges (the domain is suspended) replaced by badges that query the registries directly - deprecation notes link the migration guide; the guide itself fixed Additions: - "See also" sections, cross-references, 25 runnable examples, 12 Mermaid diagrams, new API pages for json_pointer::operator<=> and byte_container_with_subtype::operator==/!= - landing page, guides for untrusted input and performance - "unreleased" badge after versions newer than the latest release Checks: - strict documentation build (broken links/anchors fail it); CI and the publish workflow fetch the full history the build needs - weekly external link check, Mermaid syntax check in CI - check_structure.py: example titles, heading levels, alt texts, header links, docset index coverage; its unused-example check works again - all examples produce the same output on every platform Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Keep the customer links that could not be fixed A dead link on the customers page is still the evidence of where the use of the library was documented. Keep the original URLs of the entries without a working replacement (Marne, Cisco Webex Desk Camera, Philips Hue, CyberArk) and exclude exactly these URLs from the link check. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Correct the duplicate-key recipe's claim about SAX positions The SAX interface's key() receives no position either; only parse_error() does. Also note that the recipe does not report the path to the repeated key (see discussion #5085). Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Say the library is available as a single header and mention json_fwd.hpp Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Correct documentation errors found while hunting for bugs - patch/patch_inplace: list the JSON pointer errors parse_error.106-109 and out_of_range.402/404, and quote the actual parse_error.105 message. - unflatten: list parse_error.106/107/108 and out_of_range.404. - to_bson: list out_of_range.415 (binary subtype above 255) and note that 412 and 415 are new in 3.13.0. - to_string: state that string_t must be convertible to std::string, also in the StringType requirements table. - JSON Lines: a `while (input >> j)` loop also throws after the last value for concatenated JSON values; show a loop that works for both. - BON8: a string gets 0xFF only if nothing follows it in the message; a string at the end of an array or object is ended by 0xFE. - custom_string_type.hpp: add operator+=(char), which the "Always required" list asks for (json_pointer::to_string, flatten, unflatten, and diff did not compile), and an ADL int_to_string for diff and items. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Cache the release headers with functools.lru_cache Codacy (Pylint) flagged the mutable default argument that header() used as its cache. functools.lru_cache keeps the same memoization without it. The script's output is unchanged. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>
202 lines
7.7 KiB
Markdown
202 lines
7.7 KiB
Markdown
# <small>nlohmann::basic_json::</small>insert
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```cpp
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// (1)
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iterator insert(const_iterator pos, const basic_json& val);
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iterator insert(const_iterator pos, basic_json&& val);
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// (2)
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iterator insert(const_iterator pos, size_type cnt, const basic_json& val);
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// (3)
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iterator insert(const_iterator pos, const_iterator first, const_iterator last);
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// (4)
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iterator insert(const_iterator pos, initializer_list_t ilist);
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// (5)
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void insert(const_iterator first, const_iterator last);
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```
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1. Inserts element `val` into an array before iterator `pos`.
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2. Inserts `cnt` copies of `val` into an array before iterator `pos`.
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3. Inserts elements from range `[first, last)` into an array before iterator `pos`.
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4. Inserts elements from initializer list `ilist` into an array before iterator `pos`.
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5. Inserts elements from range `[first, last)` into an object.
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## Iterator invalidation
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For all cases where an element is added to an **array**, a reallocation can happen, in which case all iterators
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(including the [`end()`](end.md) iterator) and all references to the elements are invalidated. Otherwise, only the
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[`end()`](end.md) iterator is invalidated. Also, any iterator or reference after the insertion point will point to the
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same index, which is now a different value.
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For [`ordered_json`](../ordered_json.md), also adding an element to an **object** can yield a reallocation which again
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invalidates all iterators and all references. Also, any iterator or reference after the insertion point will point to
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the same index, which is now a different value.
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## Parameters
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`pos` (in)
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: iterator before which the content will be inserted; may be the `end()` iterator
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`val` (in)
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: value to insert
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`cnt` (in)
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: number of copies of `val` to insert
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`first` (in)
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: the start of the range of elements to insert
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`last` (in)
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: the end of the range of elements to insert
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`ilist` (in)
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: initializer list to insert the values from
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## Return value
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1. iterator pointing to the inserted `val`.
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2. iterator pointing to the first element inserted, or `pos` if `#!cpp cnt==0`
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3. iterator pointing to the first element inserted, or `pos` if `#!cpp first==last`
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4. iterator pointing to the first element inserted, or `pos` if `ilist` is empty
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5. (none)
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## Exception safety
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Strong exception safety: if an exception occurs, the original value stays intact.
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## Exceptions
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1. The function can throw the following exceptions:
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- Throws [`type_error.309`](../../home/exceptions.md#jsonexceptiontype_error309) if called on JSON values other than
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arrays; example: `"cannot use insert() with string"`
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- Throws [`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) if called on an
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iterator which does not belong to the current JSON value; example: `"iterator does not fit current value"`
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2. The function can throw the following exceptions:
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- Throws [`type_error.309`](../../home/exceptions.md#jsonexceptiontype_error309) if called on JSON values other than
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arrays; example: `"cannot use insert() with string"`
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- Throws [`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) if called on an
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iterator which does not belong to the current JSON value; example: `"iterator does not fit current value"`
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3. The function can throw the following exceptions:
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- Throws [`type_error.309`](../../home/exceptions.md#jsonexceptiontype_error309) if called on JSON values other than
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arrays; example: `"cannot use insert() with string"`
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- Throws [`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) if called on an
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iterator which does not belong to the current JSON value; example: `"iterator does not fit current value"`
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- Throws [`invalid_iterator.210`](../../home/exceptions.md#jsonexceptioninvalid_iterator210) if `first` and `last`
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do not belong to the same JSON value; example: `"iterators do not fit"`
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- Throws [`invalid_iterator.211`](../../home/exceptions.md#jsonexceptioninvalid_iterator211) if `first` or `last`
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are iterators into container for which insert is called; example: `"passed iterators may not belong to container"`
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- Throws [`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) if `first` or `last`
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do not point to an array; example: `"iterators first and last must point to arrays"`
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4. The function can throw the following exceptions:
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- Throws [`type_error.309`](../../home/exceptions.md#jsonexceptiontype_error309) if called on JSON values other than
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arrays; example: `"cannot use insert() with string"`
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- Throws [`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) if called on an
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iterator which does not belong to the current JSON value; example: `"iterator does not fit current value"`
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5. The function can throw the following exceptions:
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- Throws [`type_error.309`](../../home/exceptions.md#jsonexceptiontype_error309) if called on JSON values other than
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objects; example: `"cannot use insert() with string"`
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- Throws [`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) if `first` or `last`
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do not point to an object; example: `"iterators first and last must point to objects"`
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- Throws [`invalid_iterator.210`](../../home/exceptions.md#jsonexceptioninvalid_iterator210) if `first` and `last`
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do not belong to the same JSON value; example: `"iterators do not fit"`
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## Complexity
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1. Constant plus linear in the distance between `pos` and end of the container.
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2. Linear in `cnt` plus linear in the distance between `pos` and end of the container.
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3. Linear in `#!cpp std::distance(first, last)` plus linear in the distance between `pos` and end of the container.
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4. Linear in `ilist.size()` plus linear in the distance between `pos` and end of the container.
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5. `O(N*log(size() + N))`, where `N` is the number of elements to insert.
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## Examples
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??? example "Example: (1) insert element into array"
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The example shows how `insert()` is used.
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```cpp
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--8<-- "examples/insert.cpp"
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```
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Output:
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```json
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--8<-- "examples/insert.output"
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```
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??? example "Example: (2) insert copies of element into array"
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The example shows how `insert()` is used.
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```cpp
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--8<-- "examples/insert__count.cpp"
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```
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Output:
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```json
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--8<-- "examples/insert__count.output"
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```
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??? example "Example: (3) insert a range of elements into an array"
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The example shows how `insert()` is used.
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```cpp
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--8<-- "examples/insert__range.cpp"
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```
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Output:
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```json
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--8<-- "examples/insert__range.output"
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```
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??? example "Example: (4) insert elements from an initializer list into an array"
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The example shows how `insert()` is used.
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```cpp
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--8<-- "examples/insert__ilist.cpp"
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```
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Output:
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```json
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--8<-- "examples/insert__ilist.output"
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```
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??? example "Example: (5) insert a range of elements into an object"
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The example shows how `insert()` is used.
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```cpp
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--8<-- "examples/insert__range_object.cpp"
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```
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Output:
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```json
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--8<-- "examples/insert__range_object.output"
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```
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## See also
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- [emplace](emplace.md) add a value to an object
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- [emplace_back](emplace_back.md) add a value to an array
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- [push_back](push_back.md) add a value to an array/object
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- [update](update.md) merges objects
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## Version history
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1. Added in version 1.0.0.
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2. Added in version 1.0.0.
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3. Added in version 1.0.0.
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4. Added in version 1.0.0. Fixed in version 3.13.0 to copy the values before inserting; before, an `ilist` that
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referred to elements of the array being inserted into could insert wrong values, because the range insert could
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move from or shift an element before it was copied.
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5. Added in version 3.0.0.
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