basic_json::diff

static basic_json diff(const basic_json& source,
                       const basic_json& target);

Creates a JSON Patch so that value source can be changed into the value target by calling patch function.

For two JSON values source and target, the following code yields always #!cpp true:

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

Parameters

source (in): JSON value to compare from
target (in): JSON value to compare against

Return value

a JSON patch to convert the source to target

Exception safety

Strong guarantee: if an exception is thrown, there are no changes in the JSON value.

Complexity

Linear in the lengths of source and target.

Note

Currently, only remove, add, and replace operations are generated.

Example

??? 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"
```

Version history

Added in version 2.0.0.

1.1 KiB Raw Blame History