defer.hpp

// Copyright Take Vos 2022.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt)
 
#pragma once
 
#include "../macros.hpp"
#include <type_traits>
#include <functional>
 
hi_export_module(hikogui.utility.defer);
 
namespace hi { inline namespace v1 {
 
hi_export class defer {
public:
    defer() = delete;
    defer(defer &&) = delete;
    defer(defer const &) = delete;
    defer &operator=(defer &&) = delete;
    defer &operator=(defer const &) = delete;
 
    template<std::invocable<> Func>
    [[nodiscard]] defer(Func &&func) noexcept : _func(std::forward<Func>(func)) {}
 
    ~defer()
    {
        if (_func) {
            _func();
        }
    }
 
    void cancel() noexcept
    {
        _func = nullptr;
    }
 
private:
    std::function<void()> _func;
};
 
}}