std::numeric_limits<T>::max
From cppreference.com
| Defined in header <limits>
|
||
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.
Return value
T
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std::numeric_limits<T>::max()
|
/* non-specialized */
|
T()
|
bool
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true
|
char
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CHAR_MAX
|
signed char
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SCHAR_MAX
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unsigned char
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UCHAR_MAX
|
wchar_t
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WCHAR_MAX
|
char8_t (since C++20)
|
UCHAR_MAX
|
char16_t (since C++11)
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UINT_LEAST16_MAX
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char32_t (since C++11)
|
UINT_LEAST32_MAX
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short
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SHRT_MAX
|
unsigned short
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USHRT_MAX
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int
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INT_MAX
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unsigned int
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UINT_MAX
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long
|
LONG_MAX
|
unsigned long
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ULONG_MAX
|
long long (since C++11)
|
LLONG_MAX
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unsigned long long (since C++11)
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ULLONG_MAX
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float
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FLT_MAX
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double
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DBL_MAX
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long double
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LDBL_MAX
|
Example
Demonstrates the use of max() with some fundamental types and some standard library typedefs (the output is system-specific):
Run this code
#include <boost/type_index.hpp>
#include <cstddef>
#include <iomanip>
#include <iostream>
#include <limits>
#include <type_traits>
template<typename T>
void print_max_value_of()
{
constexpr T max{std::numeric_limits<T>::max()};
std::cout << std::setw(16) << boost::typeindex::type_id<T>() << ": ";
if constexpr (std::is_floating_point_v<T>)
std::cout << std::defaultfloat << max << " = " << std::hexfloat << max << '\n';
else
{
constexpr auto m{static_cast<unsigned long long>(max)};
std::cout << std::dec << m << " = " << std::hex << m << '\n';
}
}
int main()
{
std::cout << std::showbase;
print_max_value_of<bool>();
print_max_value_of<short>();
print_max_value_of<int>();
print_max_value_of<std::streamsize>();
print_max_value_of<std::size_t>();
print_max_value_of<char>();
print_max_value_of<char16_t>();
print_max_value_of<wchar_t>();
print_max_value_of<float>();
print_max_value_of<double>();
print_max_value_of<long double>();
}
Possible output:
bool: 1 = 0x1
short: 32767 = 0x7fff
int: 2147483647 = 0x7fffffff
long: 9223372036854775807 = 0x7fffffffffffffff
unsigned 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
See also
[static] (C++11) |
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) |
[static] |
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) |