Nlohmann-json

Release date: 2019-03-20
SHA-256: ce9839370f28094c71107c405affb3b08c4a098154988014cbb0800b1c44a831 (json.hpp), 237c5e66e7f8186a02804ce9dbd5f69ce89fe7424ef84adf6142e973bd9532f4 (include.zip)

ℹ️ **This release introduced a regression. Please update to [version 3.6.1](https://github.com/nlohmann/json/releases/tag/v3.6.1)!**

Summary

This release adds some **convenience functions for JSON Pointers**, introduces a [`contains`](
http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a0a45fc740637123fdf05fef970f8be47.html#a0a45fc740637123fdf05fef970f8be47) function to check if a key is present in an object, and improves the **performance of integer serialization**. Furthermore, a lot of small bug fixes and improvements have been made. All changes are backward-compatible.

:sparkles: New Features

- Overworked the public interface for JSON Pointers. The creation of JSON Pointers is simplified with [`operator/`](
http://nlohmann.github.io/json/classnlohmann_1_1json__pointer_a90a11fe6c7f37b1746a3ff9cb24b0d53.html#a90a11fe6c7f37b1746a3ff9cb24b0d53) and [`operator/=`](http://nlohmann.github.io/json/classnlohmann_1_1json__pointer_a7395bd0af29ac23fd3f21543c935cdfa.html#a7395bd0af29ac23fd3f21543c935cdfa). JSON Pointers can be inspected with [`empty`](http://nlohmann.github.io/json/classnlohmann_1_1json__pointer_a649252bda4a2e75a0915b11a25d8bcc3.html#a649252bda4a2e75a0915b11a25d8bcc3), [`back`](http://nlohmann.github.io/json/classnlohmann_1_1json__pointer_a6bd5b554c10f15672135c216893eef31.html#a6bd5b554c10f15672135c216893eef31), and [`parent_pointer`](http://nlohmann.github.io/json/classnlohmann_1_1json__pointer_afdaacce1edb7145e0434e014f0e8685a.html#afdaacce1edb7145e0434e014f0e8685a), and manipulated with [`push_back`](http://nlohmann.github.io/json/classnlohmann_1_1json__pointer_a697d12b5bd6205f8866691b166b7c7dc.html#a697d12b5bd6205f8866691b166b7c7dc) and [`pop_back`](http://nlohmann.github.io/json/classnlohmann_1_1json__pointer_a4b1ee4d511ca195bed896a3da47e264c.html#a4b1ee4d511ca195bed896a3da47e264c). 1434
- Added a boolean method [`contains`](
http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a0a45fc740637123fdf05fef970f8be47.html#a0a45fc740637123fdf05fef970f8be47) to check whether an element exists in a JSON object with a given key. Returns false when called on non-object types. 1471 1474

:bug: Bug Fixes

- Fixed a compilation issues with libc 2.12. 1483 1514
- Fixed endian conversion on PPC64. 1489
- Fixed library to compile with GCC 9. 1472 1492
- Fixed a compilation issue with GCC 7 on CentOS. 1496
- Fixed an integer overflow. 1447
- Fixed buffer flushing in serializer. 1445 1446

:zap: Improvements

- The performance of dumping integers has been greatly improved. 1411
- Added CMake parameter `JSON_Install` to control whether the library should be installed (default: on). 1330
- Fixed a lot of compiler and linter warnings. 1400 1435 1502
- Reduced required CMake version from 3.8 to 3.1. 1409 1428 1441 1498
- Added `nodiscard` attribute to `meta()`, `array()`, `object()`, `from_cbor`, `from_msgpack`, `from_ubjson`, `from_bson`, and `parse`. 1433

:hammer: Further Changes

- Added missing headers. 1500
- Fixed typos and broken links in README. 1417 1423 1425 1451 1455 1491
- Fixed documentation of parse function. 1473
- Suppressed warning that cannot be fixed inside the library. 1401 1468
- Imroved package manager suppert:
- Updated Buckaroo instructions. 1495
- Improved Meson support. 1463
- Added Conda package manager documentation. 1430
- Added NuGet package manager documentation. 1132
- Continuous Integration
- Removed unstable or deprecated Travis builders (Xcode 6.4 - 8.2) and added Xcode 10.1 builder.
- Added Clang 7 to Travis CI.
- Fixed AppVeyor x64 builds. 1374 1414
- Updated thirdparty libraries:
- Catch 1.12.0 -> 1.12.2
- Google Benchmark 1.3.0 -> 1.4.1
- Doxygen 1.8.15 -> 1.8.16

:fire: Deprecated functions

This release does not deprecate any functions. As an overview, the following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):

- Function [`iterator_wrapper`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_af1592a06bc63811886ade4f9d965045e.html#af1592a06bc63811886ade4f9d965045e) are deprecated. Please use the member function [`items()`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_afe3e137ace692efa08590d8df40f58dd.html#afe3e137ace692efa08590d8df40f58dd) instead.
- Functions [`friend std::istream& operator<<(basic_json&, std::istream&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_ab7285a92514fcdbe6de505ebaba92ea3.html#ab7285a92514fcdbe6de505ebaba92ea3) and [`friend std::ostream& operator>>(const basic_json&, std::ostream&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a9e06deabe69262c3ffc5533d32856983.html#a9e06deabe69262c3ffc5533d32856983) are deprecated. Please use [`friend std::istream& operator>>(std::istream&, basic_json&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_aaf363408931d76472ded14017e59c9e8.html#aaf363408931d76472ded14017e59c9e8) and [`friend operator<<(std::ostream&, const basic_json&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a5e34c5435e557d0bf666bd7311211405.html#a5e34c5435e557d0bf666bd7311211405) instead.

Release date: 2018-12-22
SHA-256: 8a6dbf3bf01156f438d0ca7e78c2971bca50eec4ca6f0cf59adf3464c43bb9d5 (json.hpp), 3564da9c5b0cf2e032f97c69baedf10ddbc98030c337d0327a215ea72259ea21 (include.zip)

Summary

This release introduces the support for **structured bindings** and reading from **`FILE*`**. Besides, a few bugs have been fixed. All changes are backward-compatible.

:sparkles: New Features

- **Structured bindings** are now supported for JSON objects and arrays via the [`items()`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_afe3e137ace692efa08590d8df40f58dd.html#afe3e137ace692efa08590d8df40f58dd) member function, so finally this code is possible:
cpp
for (auto& [key, val] : j.items()) {
std::cout << key << ':' << val << '\n';
}

1388 1391

- Added support for **reading from `FILE*`** to support situations in which streams are nit available or would require too much RAM. 1370 1392

:bug: Bug Fixes

- The `eofbit` was not set for input streams when the end of a stream was reached while parsing. 1340 1343
- Fixed a bug in the SAX parser for BSON arrays.

:zap: Improvements

- Added support for Clang 5.0.1 (PS4 version). 1341 1342

:hammer: Further Changes

- Added a warning for implicit conversions to the documentation: It is not recommended to use implicit conversions when reading **from** a JSON value. Details about this recommendation can be found [here](https://www.github.com/nlohmann/json/issues/958). #1363
- Fixed typos in the documentation. 1329 1380 1382
- Fixed a C4800 warning. 1364
- Fixed a `-Wshadow` warning 1346
- Wrapped `std::snprintf` calls to avoid error in MSVC. 1337
- Added code to allow installation via Meson. 1345

:fire: Deprecated functions

This release does not deprecate any functions. As an overview, the following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):

- Function [`iterator_wrapper`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_af1592a06bc63811886ade4f9d965045e.html#af1592a06bc63811886ade4f9d965045e) are deprecated. Please use the member function [`items()`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_afe3e137ace692efa08590d8df40f58dd.html#afe3e137ace692efa08590d8df40f58dd) instead.
- Functions [`friend std::istream& operator<<(basic_json&, std::istream&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_ab7285a92514fcdbe6de505ebaba92ea3.html#ab7285a92514fcdbe6de505ebaba92ea3) and [`friend std::ostream& operator>>(const basic_json&, std::ostream&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a9e06deabe69262c3ffc5533d32856983.html#a9e06deabe69262c3ffc5533d32856983) are deprecated. Please use [`friend std::istream& operator>>(std::istream&, basic_json&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_aaf363408931d76472ded14017e59c9e8.html#aaf363408931d76472ded14017e59c9e8) and [`friend operator<<(std::ostream&, const basic_json&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a5e34c5435e557d0bf666bd7311211405.html#a5e34c5435e557d0bf666bd7311211405) instead.

Release date: 2018-10-30
SHA-256: 63da6d1f22b2a7bb9e4ff7d6b255cf691a161ff49532dcc45d398a53e295835f (json.hpp), bfec46fc0cee01c509cf064d2254517e7fa80d1e7647fea37cf81d97c5682bdc (include.zip)

Summary

This release introduces three new features:

- **BSON (Binary JSON)** is next to CBOR, MessagePack, and UBJSON the fourth binary (de)serialization format supported by the library.
- **Adjustable error handlers for invalid Unicode** allows to specify the behavior when invalid byte sequences are serialized.
- **Simplified enum/JSON mapping** with a macro in case the default mapping to integers is not desired.

Furthermore, some effort has been invested in improving the **parse error messages**. Besides, a few bugs have been fixed. All changes are backward-compatible.

:sparkles: New Features

- The library can read and write a subset of **[BSON](http://bsonspec.org/) (Binary JSON)**. All data types known from JSON are supported, whereas other types more tied to MongoDB such as timestamps, object ids, or binary data are currently not implemented. See [the README](https://github.com/nlohmann/json#binary-formats-bson-cbor-messagepack-and-ubjson) for examples. 1244 1320
- The behavior when the library encounters an invalid Unicode sequence during serialization can now be controlled by defining one of three **Unicode error handlers**: (1) throw an exception (default behavior), (2) replace invalid sequences by the Unicode replacement character (U+FFFD), or (3) ignore/filter invalid sequences. See the [documentation of the `dump` function](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a50ec80b02d0f3f51130d4abb5d1cfdc5.html#a50ec80b02d0f3f51130d4abb5d1cfdc5) for examples. 1198 1314
- To easily specify a user-defined **enum/JSON mapping**, a macro `NLOHMANN_JSON_SERIALIZE_ENUM` has been introduced. See the [README section](https://github.com/nlohmann/json#specializing-enum-conversion) for more information. 1208 1323

:bug: Bug Fixes

- fixed truncation 1286 1315
- fixed an issue with std::pair 1299 1301
- fixed an issue with std::variant 1292 1294
- fixed a bug in the JSON Pointer parser

:zap: Improvements

- The **diagnosis messages for parse errors** have been improved: error messages now indicated line/column positions where possible (in addition to a byte count) and also the context in which the error occurred (e.g., "while parsing a JSON string"). Example: error `parse error at 2: syntax error - invalid string: control character must be escaped; last read: '<U+0009>'` is now reported as `parse error at line 1, column 2: syntax error while parsing value - invalid string: control character U+0009 (HT) must be escaped to \u0009 or \t; last read: '<U+0009>'`. 1280 1288 1303

:hammer: Further Changes

- improved Meson documentation 1305
- fixed some more linter warnings 1280
- fixed Clang detection for third-party Google Benchmark library 1277

:fire: Deprecated functions

This release does not deprecate any functions. As an overview, the following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):

- Function [`iterator_wrapper`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_af1592a06bc63811886ade4f9d965045e.html#af1592a06bc63811886ade4f9d965045e) are deprecated. Please use the member function [`items()`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_afe3e137ace692efa08590d8df40f58dd.html#afe3e137ace692efa08590d8df40f58dd) instead.
- Functions [`friend std::istream& operator<<(basic_json&, std::istream&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_ab7285a92514fcdbe6de505ebaba92ea3.html#ab7285a92514fcdbe6de505ebaba92ea3) and [`friend std::ostream& operator>>(const basic_json&, std::ostream&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a9e06deabe69262c3ffc5533d32856983.html#a9e06deabe69262c3ffc5533d32856983) are deprecated. Please use [`friend std::istream& operator>>(std::istream&, basic_json&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_aaf363408931d76472ded14017e59c9e8.html#aaf363408931d76472ded14017e59c9e8) and [`friend operator<<(std::ostream&, const basic_json&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a5e34c5435e557d0bf666bd7311211405.html#a5e34c5435e557d0bf666bd7311211405) instead.

Release date: 2018-10-05
SHA-256: f1327bb60c58757a3dd2b0c9c45d49503d571337681d950ec621f8374bcc14d4 (json.hpp), 9588d63557333aaa485e92221ec38014a85a6134e7486fe3441e0541a5a89576 (include.zip)

Summary

This release adds support for **GCC 4.8**. Furthermore, it adds a function [**`get_to`**](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a8a3db7d78f74232d3a6fb8f1abf69709.html#a8a3db7d78f74232d3a6fb8f1abf69709) to write a JSON value to a passed reference. Another topic of this release was the **CMake support** which has been overworked and documented.

Besides, a lot of bugs have been fixed and slight improvements have been made. All changes are backward-compatible.

:sparkles: New Features

- The library can now also built with **GCC 4.8**. Though this compiler does not fully support C++11, it can successfully compile and run the test suite. Note that bug [57824](https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57824) in GCC 4.8 still forbids to use multiline raw strings in arguments to macros. #1257
- Added new function [**`get_to`**](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a8a3db7d78f74232d3a6fb8f1abf69709.html#a8a3db7d78f74232d3a6fb8f1abf69709) to write a JSON value to a passed reference. The destination type is automatically derived which allows more succinct code compared to the `get` function. 1227 1231

:bug: Bug Fixes

- Fixed a bug in the CMake file that made `target_link_libraries` to not properly include `nlohmann_json`. 1243 1245 1260
- Fixed a warning in MSVC 2017 complaining about a constexpr if. 1204 1268 1272
- Fixed a bug that prevented compilation with ICPC. 755 1222
- Improved the SFINAE correctness to fix a bug in the conversion operator. 1237 1238
- Fixed a `-Wctor-dtor-privacy` warning. 1224
- Fixed a warning on a lambda in unevaluated context. 1225 1230
- Fixed a bug introduced in version 3.2.0 where defining `JSON_CATCH_USER` led to duplicate macro definition of `JSON_INTERNAL_CATCH`. 1213 1214
- Fixed a bug that prevented compilation with Clang 3.4.2 in RHEL 7. 1179 1249

:zap: Improvements

- Added [documentation on CMake integration](https://github.com/nlohmann/json#cmake) of the library. 1270
- Changed the CMake file to use `find_package(nlohmann_json)` without installing the library. 1202
- Improved error messages in case `operator[]` is used with the wrong combination (json.exception.type_error.305) of JSON container type and argument type. Example: "cannot use operator[] with a string argument". 1220 1221
- Added a license and version information to the Meson build file. 1252
- Removed static assertions to indicated missing `to_json` or `from_json` functions as such assertions do not play well with SFINAE. These assertions also led to problems with GMock. 960 1212 1228
- The test suite now does not wait forever if run in a wrong directory and input files are not found. 1262
- The test suite does not show deprecation warnings for deprecated functions which frequently led to confusion. 1271

:hammer: Further Changes

- GCC 4.8 and Xcode 10 were added to the [continuous integration suite](https://travis-ci.org/nlohmann/json) at Travis.
- Added [lgtm](https://lgtm.com/projects/g/nlohmann/json/context:cpp) checks to pull requests.
- Added tests for CMake integration. 1260

:fire: Deprecated functions

This release does not deprecate any functions. As an overview, the following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):

- Function [`iterator_wrapper`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_af1592a06bc63811886ade4f9d965045e.html#af1592a06bc63811886ade4f9d965045e) are deprecated. Please use the member function [`items()`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_afe3e137ace692efa08590d8df40f58dd.html#afe3e137ace692efa08590d8df40f58dd) instead.
- Functions [`friend std::istream& operator<<(basic_json&, std::istream&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_ab7285a92514fcdbe6de505ebaba92ea3.html#ab7285a92514fcdbe6de505ebaba92ea3) and [`friend std::ostream& operator>>(const basic_json&, std::ostream&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a9e06deabe69262c3ffc5533d32856983.html#a9e06deabe69262c3ffc5533d32856983) are deprecated. Please use [`friend std::istream& operator>>(std::istream&, basic_json&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_aaf363408931d76472ded14017e59c9e8.html#aaf363408931d76472ded14017e59c9e8) and [`friend operator<<(std::ostream&, const basic_json&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a5e34c5435e557d0bf666bd7311211405.html#a5e34c5435e557d0bf666bd7311211405) instead.

Release date: 2018-08-20
SHA-256: ce6b5610a051ec6795fa11c33854abebb086f0fd67c311f5921c3c07f9531b44 (json.hpp), 35ee642558b90e2f9bc758995c4788c4b4d4dec54eef95fb8f38cb4d49c8fc7c (include.zip)

Summary

This release introduces a [**SAX interface**](https://nlohmann.github.io/json/structnlohmann_1_1json__sax.html) to the library. While this may be a very special feature used by only few people, it allowed to unify all functions that consumed input and created some kind of JSON value. Internally, now all existing functions like `parse`, `accept`, `from_cbor`, `from_msgpack`, and `from_ubjson` use the SAX interface with different event processors. This allowed to separate the input processing from the value generation. Furthermore, throwing an exception in case of a parse error is now optional and up to the event processor. Finally, the JSON parser is now non-recursive (meaning it does not use the call stack, but `std::vector<bool>` to track the hierarchy of structured values) which allows to process nested input more efficiently.

Furthermore, the library finally is able to parse from **wide string types**. This is the first step toward opening the library from UTF-8 to UTF-16 and UTF-32.

This release further fixes several bugs in the library. All changes are backward-compatible.

:sparkles: New Features

- added a parser with a **SAX interface** (971, 1153)
- support to parse from **wide string types** `std::wstring`, `std::u16string`, and `std::u32string`; the input will be converted to UTF-8 (1031)
- added support for **`std::string_view`** when using C++17 (1028)
- allow to **roundtrip `std::map` and `std::unordered_map`** from JSON if key type is not convertible to string; in these cases, values are serialized to arrays of pairs (1079, 1089, 1133, 1138)

:bug: Bug Fixes

- allow to create `nullptr_t` from JSON allowing to properly roundtrip `null` values (1169)
- allow compare user-defined string types (1130)
- better support for algorithms using iterators from `items()` (1045, 1134)
- added parameter to avoid compilation error with MSVC 2015 debug builds (1114)
- re-added accidentially skipped unit tests (1176)
- fixed MSVC issue with `std::swap` (1168)

:zap: Improvements

- `key()` function for iterators returns a const reference rather than a string copy (1098)
- binary formats CBOR, MessagePack, and UBJSON now supports `float` as type for floating-point numbers (1021)

:hammer: Further Changes

- changed issue templates
- improved continuous integration: added builders for Xcode 9.3 and 9.4, added builders for GCC 8 and Clang 6, added builder for MinGW, added builders for MSVC targeting x86
- required CMake version is now at least 3.8 (1040)
- overworked CMake file wrt. packaging (1048)
- added package managers: Spack (1041) and CocoaPods (1148)
- fixed Meson include directory (1142)
- preprocessor macro `JSON_SKIP_UNSUPPORTED_COMPILER_CHECK` can skip the rejection of unsupported compilers - use at your own risk! (1128)
- preprocessor macro `JSON_INTERNAL_CATCH`/`JSON_INTERNAL_CATCH_USER` allows to control the behavior of exception handling inside the library (1187)
- added note on `char` to JSON conversion
- added note how to send security-related issue via encrypted email
- removed dependency to `std::stringstream` (1117)
- added SPDX-License-Identifier
- added updated JSON Parsing Test Suite, described in [Parsing JSON is a Minefield 💣](http://seriot.ch/parsing_json.php)
- updated to Catch 1.12.0

:fire: Deprecated functions

This release does not deprecate any functions. As an overview, the following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):

- Function [`iterator_wrapper`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_af1592a06bc63811886ade4f9d965045e.html#af1592a06bc63811886ade4f9d965045e) are deprecated. Please use the member function [`items()`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_afe3e137ace692efa08590d8df40f58dd.html#afe3e137ace692efa08590d8df40f58dd) instead.
- Functions [`friend std::istream& operator<<(basic_json&, std::istream&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_ab7285a92514fcdbe6de505ebaba92ea3.html#ab7285a92514fcdbe6de505ebaba92ea3) and [`friend std::ostream& operator>>(const basic_json&, std::ostream&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a9e06deabe69262c3ffc5533d32856983.html#a9e06deabe69262c3ffc5533d32856983) are deprecated. Please use [`friend std::istream& operator>>(std::istream&, basic_json&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_aaf363408931d76472ded14017e59c9e8.html#aaf363408931d76472ded14017e59c9e8) and [`friend operator<<(std::ostream&, const basic_json&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a5e34c5435e557d0bf666bd7311211405.html#a5e34c5435e557d0bf666bd7311211405) instead.

Release date: 2018-03-14
SHA-256: fbdfec4b4cf63b3b565d09f87e6c3c183bdd45c5be1864d3fcb338f6f02c1733 (json.hpp), 495362ee1b9d03d9526ba9ccf1b4a9c37691abe3a642ddbced13e5778c16660c (include.zip)

Summary

This release fixes several bugs in the library. All changes are backward-compatible.

:bug: Bug Fixes

- Fixed a **memory leak** occurring in the parser callback (1001).
- Different **specializations of `basic_json`** (e.g., using different template arguments for strings or objects) can now be used in assignments (972, 977, 986).
- Fixed a logical error in an iterator range check (992).

:zap: Improvements

- The parser and the serialization now support **user-defined string types** (1006, 1009).

:hammer: Further Changes

- **[Clang Analyzer](http://clang-analyzer.llvm.org)** is now used as additional static analyzer; see `make clang_analyze`.
- Overworked [README](https://github.com/nlohmann/json/blob/develop/README.md) by adding links to the [documentation](https://nlohmann.github.io/json/) (#981).

:fire: Deprecated functions

This release does not deprecate any functions. As an overview, the following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):

- Function [`iterator_wrapper`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_af1592a06bc63811886ade4f9d965045e.html#af1592a06bc63811886ade4f9d965045e) are deprecated. Please use the member function [`items()`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_afe3e137ace692efa08590d8df40f58dd.html#afe3e137ace692efa08590d8df40f58dd) instead.
- Functions [`friend std::istream& operator<<(basic_json&, std::istream&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_ab7285a92514fcdbe6de505ebaba92ea3.html#ab7285a92514fcdbe6de505ebaba92ea3) and [`friend std::ostream& operator>>(const basic_json&, std::ostream&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a9e06deabe69262c3ffc5533d32856983.html#a9e06deabe69262c3ffc5533d32856983) are deprecated. Please use [`friend std::istream& operator>>(std::istream&, basic_json&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_aaf363408931d76472ded14017e59c9e8.html#aaf363408931d76472ded14017e59c9e8) and [`friend operator<<(std::ostream&, const basic_json&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a5e34c5435e557d0bf666bd7311211405.html#a5e34c5435e557d0bf666bd7311211405) instead.