Hands-On Design Patterns with C++

Type-erased ScopeGuard

If you search online for a ScopeGuard example, you may chance upon an implementation that uses std::function instead of a class template. The implementation itself is quite simple:

class ScopeGuard {    public:    template <typename Func> ScopeGuard(Func&& func)         : commit_(false), func_(func) {}    template <typename Func> ScopeGuard(const Func& func)         : commit_(false), func_(func) {}    ~ScopeGuard() { if (!commit_) func_(); }    void commit() const noexcept { commit_ = true; }    ScopeGuard(ScopeGuard&& other)         : commit_(other.commit_),           func_(other.func_)         { other.commit(); }    private:    mutable bool commit_;    std::function<void()> func_;    ScopeGuard& operator=(const ScopeGuard&) = delete;};

Note that this ScopeGuard is a class, not a ...