std::numeric_limits::is_modulo
De cppreference.com
<metanoindex/>
<tbody> </tbody> static const bool is_modulo |
(até C++11) | |
static constexpr bool is_modulo |
(desde 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.
Especializações padrão
T
|
valor de
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
|
Exemplo
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
}
Saída:
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