/************************************************************************************
 *
 * D++, A Lightweight C++ library for Discord
 *
 * Copyright 2022 Craig Edwards and D++ contributors 
 * (https://github.com/brainboxdotcc/DPP/graphs/contributors)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 ************************************************************************************/
#pragma once
#include <dpp/export.h>
#include <utility>

namespace dpp {

	/**
	 * @brief Run some code within an if() statement only once.
	 * 
	 * Use this template like this:
	 * 
	 * ```
	 * if (dpp::run_once<struct any_unique_name_you_like_here>()) {
	 *     // Your code here
	 * }
	 * ```
	 * 
	 * @tparam T any unique 'tag' identifier name
	 * @return auto a true/false return to say if we should execute or not
	 */
	template <typename T> auto run_once() {
		static auto called = false;
		return !std::exchange(called, true);
	};

};