json/features/merge_patch.md

JSON Merge Patch

The library supports JSON Merge Patch (RFC 7386) as a patch format. The merge patch format is primarily intended for use with the HTTP PATCH method as a means of describing a set of modifications to a target resource's content. This function applies a merge patch to the current JSON value.

Instead of using JSON Pointer to specify values to be manipulated, it describes the changes using a syntax that closely mimics the document being modified. Unlike JSON Patch, a JSON Merge Patch cannot express every kind of change (e.g., it cannot reorder array elements or remove a specific array element), but it is easier to read and write for object-shaped documents.

??? example

The following code shows how a JSON Merge Patch is applied to a JSON document.

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

Output:

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

See also

• JSON Patch and Diff - a more expressive alternative that describes a sequence of operations
• JSON Pointer - the addressing scheme used by JSON Patch
• Function merge_patch