c++ - try catch finally construct - 它是在 C++11 中吗？

Question

<分区>

Answer 1

这不是放弃 RAII 的借口，但在例如:使用非 RAII 感知 API:

template<typename Functor>
struct finally_guard {
    finally_guard(Functor f)
        : functor(std::move(f))
        , active(true)
    {}

    finally_guard(finally_guard&& other)
        : functor(std::move(other.functor))
        , active(other.active)
    { other.active = false; }

    finally_guard& operator=(finally_guard&&) = delete;

    ~finally_guard()
    {
        if(active)
            functor();
    }

    Functor functor;
    bool active;
};

template<typename F>
finally_guard<typename std::decay<F>::type>
finally(F&& f)
{
    return { std::forward<F>(f) };
}

用法:

auto resource = /* acquire */;
auto guard = finally([&resource] { /* cleanup */ });
// using just
// finally([&resource] { /* cleanup */ });
// is wrong, as usual

请注意，如果您不需要翻译或以其他方式处理异常，则不需要 try block 。

虽然我的示例使用了 C++11 功能，但 C++03 也提供了相同的通用功能(尽管没有 lambda)。