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nlohmann::ordered_json_document

Defined in header <nlohmann/json_view.hpp>

using ordered_json_document = basic_json_document<ordered_json>;

This type is a basic_json_document of the ordered_json specialization: materialize() on one of its views preserves the insertion order of object keys, instead of sorting them like json_document does.

Examples

Example

The example below demonstrates how ordered_json_document preserves the insertion order of object keys when materializing.

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

using ordered_json_document = nlohmann::ordered_json_document;

int main()
{
    // ordered_json_document is basic_json_document<nlohmann::ordered_json>:
    // materialize() preserves the insertion (source) order of object keys,
    // instead of sorting them like json_document does
    ordered_json_document doc = ordered_json_document::parse(R"({"z": 1, "a": 2, "m": 3})");
    std::cout << doc.root().materialize().dump() << '\n';
}

Output:

{"z":1,"a":2,"m":3}

See also

Version history

Since version 3.13.0 unreleased.