JsonOptional.hpp File Reference

nlohmann::json support for std::optional<T>. More...

#include <nlohmann/json.hpp>
#include <optional>
#include <string_view>

Go to the source code of this file.

Classes
struct	nlohmann::adl_serializer< std::optional< T > >

Namespaces
namespace	nlohmann
namespace	ppforest2
	Binarization strategies for multiclass-to-binary reduction.
namespace	ppforest2::serialization
	JSON serialization and deserialization for ppforest2 models.

Functions
bool	ppforest2::serialization::has_value (nlohmann::json const &j, std::string_view key)
	True iff j has a non-null value at key.

Detailed Description

nlohmann::json support for std::optional<T>.

Include this header alongside <nlohmann/json.hpp> to enable transparent JSON conversion for std::optional fields:

j["key"] = std::optional<int>(42);   // writes 42
j["key"] = std::optional<int>{};     // writes null
auto opt = j["key"].get<std::optional<int>>();  // reads back