NAME¶

std::make_signed - std::make_signed

Synopsis¶

Defined in header <type_traits>
template< class T > (since C++11)
struct make_signed;

If T is an integral (except bool) or enumeration type, provides the member typedef
type which is the signed integer type corresponding to T, with the same
cv-qualifiers.

If T is signed or unsigned char, short, int, long, long long, the signed type from
this list corresponding to T is provided.

If T is an enumeration type or char, wchar_t
, char8_t
(since C++20), char16_t, char32_t, the signed integer type with the smallest rank
having the same sizeof as T is provided.

Otherwise, the behavior is undefined. (until C++20)
Otherwise, the program is ill-formed. (since C++20)

If the program adds specializations for std::make_signed, the behavior is undefined.

Member types¶

Name Definition
type the signed integer type corresponding to T

Helper types¶

template< class T > (since C++14)
using make_signed_t = typename make_signed<T>::type;

Example¶

// Run this code

#include <type_traits>

enum struct E : unsigned short {};

int main()
{
using char_type = std::make_signed_t<unsigned char>;
using int_type = std::make_signed_t<unsigned int>;
using long_type = std::make_signed_t<volatile unsigned long>;
using enum_type = std::make_signed_t<E>;

static_assert(
std::is_same_v<char_type, signed char> and
std::is_same_v<int_type, signed int> and
std::is_same_v<long_type, volatile signed long> and
std::is_same_v<enum_type, signed short>
);
}

See also¶

is_signed checks if a type is a signed arithmetic type
(C++11) (class template)
is_unsigned checks if a type is an unsigned arithmetic type
(C++11) (class template)
make_unsigned makes the given integral type unsigned
(C++11) (class template)