using decay_t = typename decay<T>::type; (C++14 起) 可能的实现template<class T> struct decay { private: typedef typename std::remove_reference<T>::type U; public: typedef typename std::conditional< std::is_array<U>::value, typename std::add_pointer<typename std::remove_extent<U>::...
1) 销毁范围 [first, last) 中的对象,如同用 for (; first != last; ++first) std::destroy_at(std::addressof(*first));2) 同(1),但按照 policy 执行。此重载只有在 std::is_execution_policy_v<std::decay_t<ExecutionPolicy>> (C++20 前) std::is_execution_policy_v<std::remove_cvref...
我认为cppreference只是使用这个术语有点松散，并假设读者意识到引用类型和值类别之间的联系。通常，隐式转...
std::decay 并删除 const 限定符 我试图更好地理解 std::decay 的工作原理。根据 cppreference ,它应该从类型中删除 const 和 volatile 分类,作为它所做的其他转换的一部分。然而,下面的函数显示“False”、“True”与“True”、“True”,正如人们所期望的那样。有人可以澄清为什么在与此处的腐烂类型匹配时需要 ...
class decay { typedef typename remove_reference<_Tp>::type __remove_type; public: typedef typename __decay_selector<__remove_type>::__type type; }; 可以看到,首先使用了std::remove_reference将_Tp的引用属性去除了,关于std::remove_reference的内容之前有讲过,这里就不赘述了,大家可以自己去看一下...
• cppreference.com:http://en.cppreference.com/w/cpp/types/decay std::decay简介 • 类模板声明 //cplusplus.comtemplate<classT>structdecay; // MS C++ 2013 template<class_Ty> structdecay {// determines decayed version of _Ty ...
std::is_execution_policy_v<std::decay_t<ExecutionPolicy>>istrue. (until C++20) std::is_execution_policy_v<std::remove_cvref_t<ExecutionPolicy>>istrue. (since C++20) Givenbinary_opas the actual binary operation: The result is non-deterministic if thebinary_opis not associative or not commut...
std::decay就是对一个类型进行退化处理,他的实现如下: template< class T > struct decay { private: typedef typename std::remove_reference::type U; public: typedef typename std::conditional< std::is_array::value, typename std::remove_extent::type*, ...
= last; ++first) std::destroy_at(std::addressof(*first)); 2) Same as (1), but executed according to policy. This overload does not participate in overload resolution unless std::is_execution_policy_v<std::decay_t<ExecutionPolicy>> is true. Parameters first, last - the range of ...
std::is_execution_policy_v<std::decay_t<ExecutionPolicy>>istrue. (until C++20) std::is_execution_policy_v<std::remove_cvref_t<ExecutionPolicy>>istrue. (since C++20) Explanation Removing is done by shifting the elements in the range in such a way that the elements that are not to be ...