std::numeric_limits<T>::infinity
来自 zh.cppreference.net
static T infinity() throw();
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(C++11 前) | |
static constexpr T infinity() noexcept;
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(C++11 起) | |
返回特殊值“正无穷”，由浮点类型 T 表示。仅当 std::numeric_limits<T>::has_infinity == true 时有意义。在 IEEE 754（最常见的浮点数二进制表示）中，正无穷是指数位全部置 1、小数位全部清零的值。
返回值
T
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std:: numeric_limits < T > :: infinity ( ) |
| /* 非特化类型 */ | T ( ) |
| bool | false |
| char | 0 |
| signed char | 0 |
| unsigned char | 0 |
| wchar_t | 0 |
| char8_t (自 C++20 起) | 0 |
| char16_t (自 C++11 起) | 0 |
| char32_t (自 C++11 起) | 0 |
| short | 0 |
| unsigned short | 0 |
| int | 0 |
| unsigned int | 0 |
| long | 0 |
| unsigned long | 0 |
| long long (自 C++11 起) | 0 |
| unsigned long long (自 C++11 起) | 0 |
| float | HUGE_VALF |
| double | HUGE_VAL |
| long double | HUGE_VALL |
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 << " is greater than " << max << '\n'; }
输出：
inf is greater than 1.79769e+308
参见
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[static]
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标识可以表示特殊值“正无穷大”的浮点类型
(公开静态成员常量) |