json_nlohmann.hpp

Go to the documentation of this file.

#pragma once
 
 
#if !defined(TAGVAL_WITH_NLOHMANN_JSON)
#if __has_include(<nlohmann/json.hpp>)
#define TAGVAL_WITH_NLOHMANN_JSON 1
#else
#define TAGVAL_WITH_NLOHMANN_JSON 0
#endif
#endif
 
#if TAGVAL_WITH_NLOHMANN_JSON
 
#include <tagval/base.hpp>
#include <tagval/error.hpp>
 
#include <nlohmann/json.hpp>
 
#include <concepts>
#include <string>
#include <string_view>
 
namespace tagval {
 
template <typename T>
    requires std::derived_from<T, detail::TagValBaseTag>
inline void to_json(::nlohmann::json& j, const T& v) {
    j = std::string{v.code()};
}
 
template <typename T>
    requires std::derived_from<T, detail::TagValBaseTag>
inline void from_json(const ::nlohmann::json& j, T& v) {
    const auto s = j.get<std::string>();
    auto exp = T::try_of(std::string_view{s});
    if (!exp) {
        throw UnknownCodeError{exp.error().message()};
    }
    v = *exp;
}
 
}  // namespace tagval
 
#endif  // TAGVAL_WITH_NLOHMANN_JSON