mirror of
https://github.com/nlohmann/json.git
synced 2026-10-12 10:13:13 +00:00
81 lines
1.3 KiB
Markdown
81 lines
1.3 KiB
Markdown
# std::swap<basic_json\>
|
|
|
|
```cpp
|
|
namespace std {
|
|
void swap(nlohmann::basic_json& j1, nlohmann::basic_json& j2);
|
|
}
|
|
```
|
|
|
|
Exchanges the values of two JSON objects.
|
|
|
|
## Parameters
|
|
|
|
`j1` (in, out)
|
|
: value to be replaced by `j2`
|
|
|
|
`j2` (in, out)
|
|
: value to be replaced by `j1`
|
|
|
|
## Exception safety
|
|
|
|
No-throw guarantee: this function never throws exceptions.
|
|
|
|
## Complexity
|
|
|
|
Constant.
|
|
|
|
## Possible implementation
|
|
|
|
```cpp
|
|
void swap(nlohmann::basic_json& j1, nlohmann::basic_json& j2)
|
|
{
|
|
j1.swap(j2);
|
|
}
|
|
```
|
|
|
|
## Examples
|
|
|
|
??? example
|
|
|
|
The following code shows how two values are swapped with `std::swap`.
|
|
|
|
```cpp
|
|
#include <iostream>
|
|
#include <iomanip>
|
|
#include <nlohmann/json.hpp>
|
|
|
|
using json = nlohmann::json;
|
|
|
|
int main()
|
|
{
|
|
// create JSON values
|
|
json j1 = {{"one", 1}, {"two", 2}};
|
|
json j2 = {1, 2, 4, 8, 16};
|
|
|
|
std::cout << "j1 = " << j1 << " | j2 = " << j2 << '\n';
|
|
|
|
// swap values
|
|
std::swap(j1, j2);
|
|
|
|
std::cout << "j1 = " << j1 << " | j2 = " << j2 << std::endl;
|
|
}
|
|
|
|
```
|
|
|
|
Output:
|
|
|
|
```json
|
|
j1 = {"one":1,"two":2} | j2 = [1,2,4,8,16]
|
|
j1 = [1,2,4,8,16] | j2 = {"one":1,"two":2}
|
|
|
|
```
|
|
|
|
## See also
|
|
|
|
- [swap](swap.md)
|
|
|
|
## Version history
|
|
|
|
- Added in version 1.0.0.
|
|
- Extended for arbitrary basic_json types in version 3.10.5.
|