json/doc/mkdocs/docs/api/basic_json/swap.md

nlohmann::basic_json::swap

// (1)
void swap(reference other) noexcept;

// (2)
void swap(reference left, reference right) noexcept;

// (3)
void swap(array_t& other);

// (4)
void swap(object_t& other);

// (5)
void swap(string_t& other);

// (6)
void swap(binary_t& other);

// (7)
void swap(typename binary_t::container_type& other);

1. Exchanges the contents of the JSON value with those of other. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated.
2. Exchanges the contents of the JSON value from left with those of right. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated. Implemented as a friend function callable via ADL.
3. Exchanges the contents of a JSON array with those of other. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated.
4. Exchanges the contents of a JSON object with those of other. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated.
5. Exchanges the contents of a JSON string with those of other. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated.
6. Exchanges the contents of a binary value with those of other. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated.
7. Exchanges the contents of a binary value with those of other. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated. Unlike version (6), no binary subtype is involved.

Parameters

other (in, out)

value to exchange the contents with

left (in, out)

value to exchange the contents with

right (in, out)

value to exchange the contents with

Exceptions

1. No-throw guarantee: this function never throws exceptions.
2. No-throw guarantee: this function never throws exceptions.
3. Throws type_error.310 if called on JSON values other than arrays; example: "cannot use swap() with boolean"
4. Throws type_error.310 if called on JSON values other than objects; example: "cannot use swap() with boolean"
5. Throws type_error.310 if called on JSON values other than strings; example: "cannot use swap() with boolean"
6. Throws type_error.310 if called on JSON values other than binaries; example: "cannot use swap() with boolean"
7. Throws type_error.310 if called on JSON values other than binaries; example: "cannot use swap() with boolean"

Complexity

Constant.

Examples

??? example "Example: Swap JSON value (1, 2)"

The example below shows how JSON values can be swapped with `swap()`.

```cpp
--8<-- "examples/swap__reference.cpp"
```

Output:

```json
--8<-- "examples/swap__reference.output"
```

??? example "Example: Swap array (3)"

The example below shows how arrays can be swapped with `swap()`.

```cpp
--8<-- "examples/swap__array_t.cpp"
```

Output:

```json
--8<-- "examples/swap__array_t.output"
```

??? example "Example: Swap object (4)"

The example below shows how objects can be swapped with `swap()`.

```cpp
--8<-- "examples/swap__object_t.cpp"
```

Output:

```json
--8<-- "examples/swap__object_t.output"
```

??? example "Example: Swap string (5)"

The example below shows how strings can be swapped with `swap()`.

```cpp
--8<-- "examples/swap__string_t.cpp"
```

Output:

```json
--8<-- "examples/swap__string_t.output"
```

??? example "Example: Swap string (6)"

The example below shows how binary values can be swapped with `swap()`.

```cpp
--8<-- "examples/swap__binary_t.cpp"
```

Output:

```json
--8<-- "examples/swap__binary_t.output"
```

See also

• std::swap<basic_json>

Version history

1. Since version 1.0.0.
2. Since version 1.0.0.
3. Since version 1.0.0.
4. Since version 1.0.0.
5. Since version 1.0.0.
6. Since version 3.8.0.
7. Since version 3.8.0.