WhisperCom/libs/json/doc/mkdocs/docs/features/json_patch.md

JSON Patch and Diff

Patches

JSON Patch (RFC 6902) defines a JSON document structure for expressing a sequence of operations to apply to a JSON) document. With the patch function, a JSON Patch is applied to the current JSON value by executing all operations from the patch.

??? example

The following code shows how a JSON patch is applied to a value.

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

Output:

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

Diff

The library can also calculate a JSON patch (i.e., a diff) given two JSON values.

!!! success "Invariant"

For two JSON values *source* and *target*, the following code yields always true:

```cüü
source.patch(diff(source, target)) == target;
```

??? example

The following code shows how a JSON patch is created as a diff for two JSON values.

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

Output:

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