// Copyright(c) 2015-present, Gabi Melman & spdlog contributors. // Distributed under the MIT License (http://opensource.org/licenses/MIT) #pragma once #include <atomic> #include <utility> // null, no cost dummy "mutex" and dummy "atomic" int namespace spdlog { namespace details { struct null_mutex { void lock() const {} void unlock() const {} bool try_lock() const { return true; } }; struct null_atomic_int { int value; null_atomic_int() = default; explicit null_atomic_int(int new_value) : value(new_value) {} int load(std::memory_order = std::memory_order_relaxed) const { return value; } void store(int new_value, std::memory_order = std::memory_order_relaxed) { value = new_value; } int exchange(int new_value, std::memory_order = std::memory_order_relaxed) { std::swap(new_value, value); return new_value; // return value before the call } }; } // namespace details } // namespace spdlog