Fix CI: json_view access tests without exceptions and on clang 3.6

- ci_test_noexceptions: the element access tests compare the exceptions
  of json_view and basic_json through exception_of(), which catches them
  outside a CHECK_THROWS; with JSON_NOEXCEPTION the first one aborted the
  test. Compile those comparisons only with exceptions.
- clang 3.6: value-initialize a const json_view, as in the tests of
  json-view/10-view-document.
- Format three new documentation examples with the pinned astyle, which
  the "check" job runs once it gets past the amalgamation step.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

docs/mkdocs/docs/examples/basic_json_view__cbegin.cpp

@@ -15,7 +15,7 @@ int main()
     const auto values = measurements.root();
 
     const int sum = std::accumulate(values.cbegin(), values.cend(), 0,
-                                     [](int total, const json_view & v)
+                                    [](int total, const json_view & v)
     {
         return total + v.materialize().get<int>();
     });

docs/mkdocs/docs/examples/basic_json_view__cend.cpp

@@ -15,7 +15,7 @@ int main()
     const auto records = batch.root();
 
     const bool all_objects = std::all_of(records.cbegin(), records.cend(),
-                                          [](const json_view & v)
+                                         [](const json_view & v)
     {
         return v.is_object();
     });

docs/mkdocs/docs/examples/basic_json_view__type_name.cpp

@@ -13,7 +13,10 @@ int main()
     json_document bad = json_document::parse("[1, 2, 3]");
     json_document failed = json_document::parse("not json", /* allow_exceptions */ false);
 
-    for (const json_view v : { good.root(), bad.root(), failed.root() })
+    for (const json_view v :
+            {
+                good.root(), bad.root(), failed.root()
+            })
     {
         if (v.is_object())
         {

tests/src/unit-json_view.cpp

@@ -387,6 +387,7 @@ TEST_CASE("json_view")
 
 namespace
 {
+#if !defined(JSON_NOEXCEPTION)
 // the exception a call throws, or "" if it throws none
 template<typename F>
 std::string exception_of(F f)
@@ -401,6 +402,7 @@ std::string exception_of(F f)
     }
     return "";
 }
+#endif
 
 // compares a view with the ordered_json value materialize() gives for it:
 // types, sizes, elements and members (by index, key, and iteration), in
@@ -569,6 +571,7 @@ TEST_CASE("json_view element access and iteration")
             const json_document d = json_document::parse(text);
             const json_view v = d.root();
             const json j = v.materialize();
+#if !defined(JSON_NOEXCEPTION)
             if (!j.is_object())
             {
                 CHECK(exception_of([&] { static_cast<void>(v["a"]); }) == exception_of([&] { static_cast<void>(j["a"]); }));
@@ -590,6 +593,7 @@ TEST_CASE("json_view element access and iteration")
                 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()); }));
             }
+#endif
             CHECK(v.contains("a") == j.contains("a"));
             CHECK(v.count("a") == j.count("a"));
             CHECK((v.find("a") == v.end()) == (j.find("a") == j.end())); // NOLINT(readability-container-contains): find() is what is tested
@@ -601,7 +605,7 @@ TEST_CASE("json_view element access and iteration")
         CHECK(!d.root()["a"][0]);
         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;
+        const json_view invalid{};
         CHECK(invalid.begin() == invalid.end());
         CHECK(std::string(invalid.type_name()) == "discarded");
         CHECK_THROWS_WITH_AS(invalid["a"], "[json.exception.type_error.305] cannot use operator[] with a string argument with discarded", json::type_error&);