std::numeric_limits<T>::infinity
来自cppreference.com
< cpp | types | numeric limits
static T infinity() throw(); |
(C++11 前) | |
| static constexpr T infinity() noexcept; |
(C++11 起) | |
返回浮点类型 T 所表示的特殊值“正无穷大”。只有在 std::numeric_limits<T>::has_infinity == true 时才有意义。在最常见的浮点数二进制表示 IEEE 754 中，正无穷大是所有指数位是 1 而所有尾数位是 0 的值。
[编辑] 返回值
T
|
std::numeric_limits<T>::infinity() |
| /* 未特化 */ | T() |
| bool | false |
| char | 0 |
| signed char | 0 |
| unsigned char | 0 |
| wchar_t | 0 |
| char8_t (C++20 起) | 0 |
| char16_t (C++11 起) | 0 |
| char32_t (C++11 起) | 0 |
| short | 0 |
| unsigned short | 0 |
| int | 0 |
| unsigned int | 0 |
| long | 0 |
| unsigned long | 0 |
| long long (C++11 起) | 0 |
| unsigned long long (C++11 起) | 0 |
| float | HUGE_VALF |
| double | HUGE_VAL |
| long double | HUGE_VALL |
[编辑] 示例
运行此代码
#include <iostream> #include <limits> int main() { double max = std::numeric_limits<double>::max(); double inf = std::numeric_limits<double>::infinity(); if (inf > max) std::cout << inf << " 大于 " << max << '\n'; }
输出：
inf 大于 1.79769e+308
[编辑] 参阅
| [静态] |
鉴别能表示特殊值“正无穷大”的浮点数类型 (公开静态成员常量) |
