amorfo77/json
1
0
Fork 0
mirror of https://github.com/nlohmann/json.git synced 2026-10-04 13:40:33 +00:00
Code Issues Packages Projects Releases Wiki Activity

deploy: 63c10a51fc

Browse Source
This commit is contained in:
nlohmann
2026-10-03 05:43:12 +00:00
parent 2aaa1d24ef
commit a410b4f40f
741 changed files with 8115 additions and 2252 deletions
Download Patch File Download Diff File Expand all files Collapse all files
api/basic_json/operator_ne/index.md
+14 -13
View File
@@ -9,17 +9,9 @@ bool operator!=(const_reference lhs, const ScalarType rhs) noexcept; // (2)
template<typename ScalarType>
bool operator!=(ScalarType lhs, const const_reference rhs) noexcept; // (2)
// since C++20
class basic_json {
bool operator!=(const_reference rhs) const noexcept; // (1)
template<typename ScalarType>
bool operator!=(ScalarType rhs) const noexcept; // (2)
};
```
1. Compares two JSON values for inequality. Returns `!(lhs == rhs)` (until C++20) or `!(*this == rhs)` (since C++20).
1. Compares two JSON values for inequality. Returns `!(lhs == rhs)`.
- This means the comparison is simply the logical negation of `operator==`, including for special values like `NaN` and `discarded`.
@@ -49,6 +41,10 @@ Linear.
## Notes
C++20
Since C++20, `basic_json` declares no `operator!=`. The compiler rewrites `a != b` as `!(a == b)` using [`operator==`](https://json.nlohmann.me/api/basic_json/operator_eq/index.md), so the result is the same as described above.
Comparing `NaN` and `discarded`
Since `operator!=` is defined as `!(a == b)`, the behavior for special values follows that of `operator==`:
@@ -58,7 +54,7 @@ Since `operator!=` is defined as `!(a == b)`, the behavior for special values fo
## Examples
Example
Example: (1) compare JSON values
The example demonstrates comparing several JSON types.
@@ -98,7 +94,7 @@ Output:
"foo" != "bar" true
```
Example
Example: (2) compare JSON values with `nullptr`
The example demonstrates comparing several JSON types against the null pointer (JSON `null`).
@@ -137,7 +133,12 @@ Output:
null != nullptr false
```
## See also
- [operator==](https://json.nlohmann.me/api/basic_json/operator_eq/index.md) comparison: equal
- [operator\<=>](https://json.nlohmann.me/api/basic_json/operator_spaceship/index.md) comparison: 3-way (C++20)
## Version history
1. Added in version 1.0.0. Added C++20 member functions in version 3.11.0. Changed in version 3.13.0 to remove special-casing for `NaN` and `discarded` values; `operator!=` now consistently means `!(a == b)`.
1. Added in version 1.0.0. Added C++20 member functions in version 3.11.0. Changed in version 3.13.0 to remove special-casing for `NaN` and `discarded` values; `operator!=` now consistently means `!(a == b)`.
1. Added in version 1.0.0. Added a C++20 member function in version 3.11.0. Changed in version 3.13.0 unreleased to remove special-casing for `NaN` and `discarded` values; `operator!=` now consistently means `!(a == b)`. Removed the C++20 member function in version 3.13.0 unreleased; since C++20, the compiler rewrites `a != b` using `operator==`.
1. Added in version 1.0.0. Changed in version 3.13.0 unreleased to remove special-casing for `NaN` and `discarded` values; `operator!=` now consistently means `!(a == b)`. Since C++20, the compiler rewrites `a != b` using `operator==`.