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numeric_limits::max_exponent | ||||
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staticconstint max_exponent; | (until C++11) | |
staticconstexprint max_exponent; | (since C++11) | |
The value ofstd::numeric_limits<T>::max_exponent is the largest positive numbern such that\(\scriptsize r^{n-1}\)rn-1
, wherer isstd::numeric_limits<T>::radix, is a representable finite value of the floating-point typeT.
T | value ofstd::numeric_limits<T>::max_exponent |
| /* non-specialized */ | 0 |
| bool | 0 |
| char | 0 |
| signedchar | 0 |
| unsignedchar | 0 |
| wchar_t | 0 |
| char8_t(since C++20) | 0 |
| char16_t(since C++11) | 0 |
| char32_t(since C++11) | 0 |
| short | 0 |
| unsignedshort | 0 |
| int | 0 |
| unsignedint | 0 |
| long | 0 |
| unsignedlong | 0 |
| longlong(since C++11) | 0 |
| unsignedlonglong(since C++11) | 0 |
| float | FLT_MAX_EXP |
| double | DBL_MAX_EXP |
| longdouble | LDBL_MAX_EXP |
Demonstrates the relationships ofmax_exponent,max_exponent10, andmax() for the typefloat:
#include <iostream>#include <limits> int main(){std::cout<<"max() = "<<std::numeric_limits<float>::max()<<'\n'<<"max_exponent10 = "<<std::numeric_limits<float>::max_exponent10<<'\n'<<std::hexfloat<<'\n'<<"max() = "<<std::numeric_limits<float>::max()<<'\n'<<"max_exponent = "<<std::numeric_limits<float>::max_exponent<<'\n';}
Output:
max() = 3.40282e+38max_exponent10 = 38 max() = 0x1.fffffep+127max_exponent = 128
[static] | the smallest negative power of ten that is a valid normalized floating-point value (public static member constant)[edit] |
[static] | one more than the smallest negative power of the radix that is a valid normalized floating-point value (public static member constant)[edit] |
[static] | the largest integer power of 10 that is a valid finite floating-point value (public static member constant)[edit] |
