spdlog/include/spdlog/mdc.h

#pragma once

#include <spdlog/common.h>

#include <map>
#include <string>

namespace spdlog {
class SPDLOG_API mdc {
public:
    using mdc_map_t = std::map<std::string, std::string>;

    static void put(const std::string &key, const std::string &value) { get_context()[key] = value; }

    static std::string get(const std::string &key) {
        auto &context = get_context();
        auto it = context.find(key);
        if (it != context.end()) {
            return it->second;
        }
        return "";
    }

    static void remove(const std::string &key) { get_context().erase(key); }

    static void clear() { get_context().clear(); }

    static mdc_map_t &get_context() {
        static thread_local mdc_map_t context;
        return context;
    }
};

}  // namespace spdlog