The specialization std::conjunction<B1, ..., BN> has a public and unambiguous base that is if sizeof...(B) == 0, std::true_type; otherwise the first type Bi in B1, ..., BN for which bool(Bi::value) == false, o
true_typestd::integral_constant<bool,true> false_typestd::integral_constant<bool,false> Member types NameDefinition value_typeT typestd::integral_constant<T, v> Member constants NameValue constexprTvalue [static] v (public static member constant) ...
the name of a variable or a function in scope, regardless of type, such as std::cin or std::endl. Even if the variable's type is rvalue reference, the expression consisting of its name is an lvalue expression; (变量,函数都是左值) a function call or an overloaded operator expression o...
预定义常量(true、false或nullptr) 以存储类说明符constexpr和对象类型声明的变量 或者(递归地)在结构体或联合体类型的具名常量上应用成员访问运算符.的后缀表达式。 6)复合字面量常量,为 带有存储类说明符constexpr的复合字面量 (递归地)在结构体或联合体类型的复合字面量常量上应用成员访问运算符.的后缀表达式。
1) 如果虚构的函数定义 To test() { return std::declval<From>(); } 良构,(即 std::declval<From>() 能用隐式转换转换为 To,或 From 和To 均为可有 cv 限定的 void),那么提供的成员常量 value 等于true。否则,value 等于false。对于此项检查而言,不认为返回语句中的 std::declval 是ODR 使用。
if ( strpos( $keywrd, "std::" ) !== false ) { $post_keywords = explode( "::", $keywrd); $keywords[] = $post_keywords[ count( $post_keywords ) - 1 ];} else if ( strpos( $keywrd, ":" ) !== false ) { $post_keywords = explode( ":", $keywrd); ...
(std::get,std::tuple_element,std::tuple_size) (exposition-only concept*) Helper classes std::tuple_size<std::tuple> (C++11) obtains the size of atuple (class template specialization) std::tuple_element<std::tuple> (C++11) obtains the type of the specified element ...
std::suspend_always的关键信息是constexpr bool await_ready() const noexcept { return false; } std::suspend_never自然相反constexpr bool await_ready() const noexcept { return true; } 所以对于initial_suspend返回suspend_never的即表示协程立刻启动,而suspend_always则表示后续resume调用时才会启动。
true_type std::integral_constant<bool, true> false_type std::integral_constant<bool, false> Primary type categories is_void (C++11) checks if a type is void (class template) is_null_pointer (C++11)(DR*) checks if a type is std::nullptr_t (class template) is_integral (C++...
false); printf("%d %d\n", true ^ true, true + true); printf("%zu\n", alignof(short)); } Possible output: 0 1 1 0 2 2 References C17 standard (ISO/IEC 9899:2018): 7.15 Alignment <stdalign.h> (p: 196) 7.18 Boolean type and values <stdbool.h> (p: 210) 7.19 Common...