Release date: 2017-12-29

SHA-256: c9b3591f1bb94e723a0cd7be861733a3a555b234ef132be1e9027a0364118c4c

This release fixes small issues in the implementation of **JSON Pointer** and **JSON Patch**. All changes are backward-compatible.

- :bug: The **"copy" operation of JSON Patch** ([RFC 6902](https://tools.ietf.org/html/rfc6902)) requests that it is an error if the target path points into a non-existing array or object (see #894 for a detailed description). This release fixes the implementation to detect such invalid target paths and throw an exception.
- :bug: An **array index in a JSON Pointer** ([RFC 6901](https://tools.ietf.org/html/rfc6901)) must be an integer. This release fixes the implementation to throw an exception in case invalid array indices such as `10e2` are used.
- :white_check_mark: Added the [JSON Patch tests](https://github.com/json-patch/json-patch-tests) from Byron Ruth and Mike McCabe.
- :memo: Fixed the documentation of the [`at(ptr)` function with JSON Pointers](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a8ab61397c10f18b305520da7073b2b45.html#a8ab61397c10f18b305520da7073b2b45) to list all possible exceptions (see #888).
- :memo: Updated the [container overview documentation](https://nlohmann.github.io/json/) (see #883).
- :wrench: The CMake files now respect the [`BUILD_TESTING`](https://cmake.org/cmake/help/latest/module/CTest.html?highlight=build_testing) option (see #846, #885)
- :rotating_light: Fixed some compiler warnings (see #858, #882).

:fire: To unify the interfaces and to improve similarity with the STL, the following functions are deprecated since version 3.0.0 and will be removed in the next major version (i.e., 4.0.0):

- [`friend std::istream& operator<<(basic_json&, std::istream&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_ab7285a92514fcdbe6de505ebaba92ea3.html#ab7285a92514fcdbe6de505ebaba92ea3)
- [`friend std::ostream& operator>>(const basic_json&, std::ostream&)`](http://nlohmann.github.io/json/classnlohmann_1_1basic__json_a9e06deabe69262c3ffc5533d32856983.html#a9e06deabe69262c3ffc5533d32856983)

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.