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std::make_signed(3)	       C++ Standard Libary	     std::make_signed(3)

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 mem-
     ber 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)

http://cppreference.com 	   2024.06.10		     std::make_signed(3)
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