json/api/basic_json/object_comparator_t.md

nlohmann::basic_json::object_comparator_t

using object_comparator_t = typename object_t::key_compare;
// or
using object_comparator_t = default_object_comparator_t;

The comparator used by object_t. Defined as #!cpp typename object_t::key_compare if available, and default_object_comparator_t otherwise.

Examples

??? example

The example below demonstrates the used object comparator.

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

Output:

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

Version history

• Added in version 3.0.0.
• Changed to be conditionally defined as #!cpp typename object_t::key_compare or default_object_comparator_t in version 3.11.0.
• Fixed the fallback to default_object_comparator_t, which previously failed to compile for object types without a key_compare member type, in version 3.13.0.