std::numeric_limits::max - cppreference.com (original) (raw)
| Defined in header | | | | -------------------------------------------------------------------------- | | ------------- | | static T max() throw(); | | (until C++11) | | static constexpr T max() noexcept; | | (since C++11) |
Returns the maximum finite value representable by the numeric type T. Meaningful for all bounded types.
[edit] Return value
| T | std::numeric_limits<T>::max() |
|---|---|
| /* non-specialized */ | T() |
| bool | true |
| char | CHAR_MAX |
| signed char | SCHAR_MAX |
| unsigned char | UCHAR_MAX |
| wchar_t | WCHAR_MAX |
| char8_t (since C++20) | UCHAR_MAX |
| char16_t (since C++11) | UINT_LEAST16_MAX |
| char32_t (since C++11) | 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 (since C++11) | LLONG_MAX |
| unsigned long long (since C++11) | ULLONG_MAX |
| float | FLT_MAX |
| double | DBL_MAX |
| long double | LDBL_MAX |
[edit] Example
Demonstrates the use of max() with some fundamental types and some standard library typedefs (the output is system-specific):
#include <boost/type_index.hpp> #include #include #include #include #include template void print_max_value_of() { constexpr T max{std::numeric_limits::max()}; std::cout << std::setw(16) << boost::typeindex::type_id() << ": "; if constexpr (std::is_floating_point_v) std::cout << std::defaultfloat << max << " = " << std::hexfloat << max << '\n'; else { constexpr auto m{static_cast(max)}; std::cout << std::dec << m << " = " << std::hex << m << '\n'; } } int main() { std::cout << std::showbase; print_max_value_of(); print_max_value_of(); print_max_value_of(); print_max_value_of<std::streamsize>(); print_max_value_of<std::size_t>(); print_max_value_of(); print_max_value_of(); print_max_value_of(); print_max_value_of(); print_max_value_of(); print_max_value_of(); }
Possible output:
bool: 1 = 0x1
short: 32767 = 0x7fff
int: 2147483647 = 0x7fffffff
long: 9223372036854775807 = 0x7fffffffffffffffunsigned long: 18446744073709551615 = 0xffffffffffffffff char: 127 = 0x7f char16_t: 65535 = 0xffff wchar_t: 2147483647 = 0x7fffffff float: 3.40282e+38 = 0x1.fffffep+127 double: 1.79769e+308 = 0x1.fffffffffffffp+1023 long double: 1.18973e+4932 = 0xf.fffffffffffffffp+16380
[edit] See also
| | returns the lowest finite value of the given type, i.e. the most negative value for signed types, 0 for unsigned types (public static member function) [edit] | | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | returns the smallest finite value of the given non-floating-point type, or the smallest positive normal value of the given floating-point type (public static member function) [edit] |