json/api/basic_json/object_comparator_t/index.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 typename object_t::key_compare if available, and default_object_comparator_t otherwise.

Examples

Example

The example below demonstrates the used object comparator.

#include <iostream>
#include <nlohmann/json.hpp>

using json = nlohmann::json;

int main()
{
    std::cout << std::boolalpha
              << "json::object_comparator_t(\"one\", \"two\") = " << json::object_comparator_t{}("one", "two") << "\n"
              << "json::object_comparator_t(\"three\", \"four\") = " << json::object_comparator_t{}("three", "four") << std::endl;
}

Output:

json::object_comparator_t("one", "two") = true
json::object_comparator_t("three", "four") = false

Version history

• Added in version 3.0.0.
• Changed to be conditionally defined as typename object_t::key_compare or default_object_comparator_t in version 3.11.0.