#include <iostream> #include <type_traits> class A {}; int main() { std::cout << std::boolalpha; std::cout << std::is_floating_point<A>::value << '\n'; std::cout << std::is_floating_point<float>::value << '\n'; std::cout << std::is_floating_point<float&>::value...
如果程序添加了 std::is_floating_point 或std::is_floating_point_v 的特化,那么行为未定义。 模板形参T - 要检查的类型 辅助变量模板template< class T > constexpr bool is_floating_point_v = is_floating_point<T>::value; (C++17 起) 继承...
template< class T > struct is_floating_point; (C++11 起) 检查T 是否为浮点类型。若 T 为float、 double、 long double 为浮点类型,包含任何 cv 限定变体,则提供等于 true 的成员常量 value 。否则, value 等于false。 添加is_floating_point 或is_floating_point_v (C++17 起) 的特化的程序行为未...
问C++ std::enable_if区分浮点数和符号数？EN如何区分有符号数字和浮点数？使用std::is_floating_poin...
std::chrono::treat_as_floating_point 特征帮助确定时长是否能转换成拥有另一种不同计次周期的时长。 两个时长间的隐式转换通常依赖于时长的计次周期。然而若 std::chrono::treat_as_floating_point<Rep>::value 为Template:true 则不管计次周期如何,均可发生隐式转换。
inline constexpr bool treat_as_floating_point_v = treat_as_floating_point<Rep>::value; (C++17 起) 特化可对程序定义类型特化 std::chrono::treat_as_floating_point。 示例运行此代码 #include <iostream> #include <chrono> #include <thread> void timed_piece_of_code() { std::chrono::millisecon...
function std::setprecision <iomanip> /*unspecified*/ setprecision (int n); Set decimal precision Sets thedecimal precisionto be used to format floating-point values on output operations. Behaves as if memberprecisionwere called withnas argument on the stream on which it is inserted/extracted as ...
std::chrono::time_point std::chrono::time_point::max std::chrono::time_point::min std::chrono::time_point::operators (operator-) std::chrono::time_point::time_point std::chrono::time_point::time_since_epoch std::chrono::time_point_cast std::chrono::treat_as_floating_point std::cl...
浮点型(Floating-Point Types) float: 单精度浮点数 double: 双精度浮点数 long double: 更长的双精度浮点数示例代码: cpp #include <iostream> int main() { float f = 3.14f; double d = 2.718; long double ld = 1.6180339887498948482; std::cout << "f = " << f << std::endl; ...
std::chrono::time_point::max std::chrono::time_point::min std::chrono::time_point::operators (operator-) std::chrono::time_point::time_point std::chrono::time_point::time_since_epoch std::chrono::time_point_cast std::chrono::treat_as_floating_point std::clock std::clock_t std::...