用于定义整型常数变量的类,在<type_traits>中广泛应用,最直接的使用是定义了true_type和false_type, 其为对bool类型的特化
#include <iostream> #include <type_traits> using namespace std; int main() { std::cout << "This Demo is that type_traits: integral_constant" << std::endl; std::integral_constant<int, 10> int10; std::cout << "The Const Value: " << int10.value << std::endl; std::integral_constant<unsigned short int, 20> shortInt20; std::cout << "The Const Value: " << shortInt20.value << std::endl; std::cout << "Bool Integral_constent " << std::endl; std::cout << "true : " << true_type::value << std::endl; std::cout << "false: " << false_type::value << std::endl; return 0; }