std::numeric_limits::is_modulo - cppreference.com

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`static const bool is_modulo`		(fino al c++11)

`static constexpr bool is_modulo`		(dal C++11)

The value of std::numeric_limits<T>::is_modulo is true for all arithmetic types T that handle overflows with modulo arithmetic, that is, if the result of addition, subtraction, multiplication, or division of this type would fall outside the range [min(), max()], the value returned by such operation differs from the expected value by a multiple of max()-min()+1.

Specializzazioni standard


`T`	valore di `std::numeric_limits<T>::is_modulo` Original: value of `std::numeric_limits<T>::is_modulo` The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

/* non-specialized */	`false`

`bool`	`false`

`char`	`true`

`signed char`	`true`

`unsigned char`	`true`

`wchar_t`	`true`

`char16_t`	`true`

`char32_t`	`true`

`short`	`true`

`unsigned short`	`true`

`int`	`true`

`unsigned int`	`true`

`long`	`true`

`unsigned long`	`true`

`long long`	`true`

`unsigned long long`	`true`

`float`	`false`

`double`	`false`

`long double`	`false`

Esempio

Demonstrates the behavior of modulo types

#include <iostream>
#include <type_traits>
#include <limits>

template<class T>
typename std::enable_if<std::numeric_limits<T>::is_modulo>::type
    check_overflow()
{
    std::cout << "\nmax value is " << std::numeric_limits<T>::max() << '\n'
              << "min value is " << std::numeric_limits<T>::min() << '\n'
              << "max value + 1 is " << std::numeric_limits<T>::max()+1 << '\n';
}

int main()
{
    check_overflow<int>();
    check_overflow<unsigned long>();
    // check_overflow<float>(); // compile-time error, not a modulo type
}

Output:

max value is 2147483647
min value is -2147483648
max value + 1 is -2147483648

max value is 18446744073709551615
min value is 0
max value + 1 is 0

Vedi anche


is_integer [statico]	identifica i tipi interi Original: identifies integer types The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (pubblico membro statico costante) [modifica]

is_iec559 [statico]	individua le IEC 559/IEEE 754 tipi a virgola mobile Original: identifies the IEC 559/IEEE 754 floating-point types The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (pubblico membro statico costante) [modifica]

is_exact [statico]	identifica i tipi esatti Original: identifies exact types The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (pubblico membro statico costante) [modifica]