std::numeric_limits::max
STD：：数字[医]限制：最大限度
| static T max( | | (until C++11) |
|---|---|---|
| static constexpr T max( | | (since C++11) |
返回可由数值类型表示的最大值。T对所有有界类型都有意义。
返回值
| T | std::numeric_limits |
|---|---|
| /* non-specialized */ | T( |
| bool | true |
| char | CHAR_MAX |
| signed char | SCHAR_MAX |
| unsigned char | UCHAR_MAX |
| wchar_t | WCHAR_MAX |
| char16_t | UINT_LEAST16_MAX |
| char32_t | UINT_LEAST32_MAX |
| short | SHRT_MAX |
| unsigned short | USHRT_MAX |
| int | INT_MAX |
| unsigned int | UINT_MAX |
| long | LONG_MAX |
| unsigned long | ULONG_MAX |
| long long | LLONG_MAX |
| unsigned long long | ULLONG_MAX |
| float | FLT_MAX |
| double | DBL_MAX |
| long double | LDBL_MAX |
例外
| (none) | (until C++11) |
|---|---|
| noexcept specification: noexcept | (since C++11) |
例
演示使用max%28%29和一些基本类型和一些标准库类型%28，输出是特定于系统的%29。
二次
#include <limits>
#include <cstddef>
#include <iostream>
int main()
{
std::cout << "short: " << std::dec << std::numeric_limits<short>::max()
<< " or " << std::hex << std::showbase << std::numeric_limits<short>::max() << '\n'
<< "int: " << std::dec << std::numeric_limits<int>::max()
<< " or " << std::hex << std::numeric_limits<int>::max() << '\n' << std::dec
<< "streamsize: " << std::dec << std::numeric_limits<std::streamsize>::max()
<< " or " << std::hex << std::numeric_limits<std::streamsize>::max() << '\n'
<< "size_t: " << std::dec << std::numeric_limits<std::size_t>::max()
<< " or " << std::hex << std::numeric_limits<std::size_t>::max() << '\n'
<< "float: " << std::numeric_limits<float>::max()
<< " or " << std::hexfloat << std::numeric_limits<float>::max() << '\n'
<< "double: " << std::defaultfloat << std::numeric_limits<double>::max()
<< " or " << std::hexfloat << std::numeric_limits<double>::max() << '\n';
}
二次
产出：
二次
short: 32767 or 0x7fff
int: 2147483647 or 0x7fffffff
size_t: 18446744073709551615 or 0xffffffffffffffff
streamsize: 9223372036854775807 or 0x7fffffffffffffff
float: 3.40282e+38 or 0x1.fffffep+127
double: 1.79769e+308 or 0x1.fffffffffffffp+1023
二次
另见
| lowest static | returns the lowest finite value of the given type (public static member function) |
|---|---|
| min static | returns the smallest finite value of the given type (public static member function) |
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