std::real(std::complex)

Defined in header <complex>
	(1)
template < class T > T real( const std::complex <T> & z ) ;			(until C++14)
template < class T > constexpr T real( const std::complex <T> & z ) ;			(since C++14)
Additional overloads (since C++11)
Defined in header <complex>
		(A)
float       real( float f ) ; double      real( double f ); long double real( long double f ) ;				(until C++14)
constexpr float       real( float f ) ; constexpr double      real( double f ); constexpr long double real( long double f ) ;				(since C++14) (until C++23)
template < class FloatingPoint > constexpr FloatingPoint real( FloatingPoint f ) ;				(since C++23)
			(B)
template < class Integer > double real( Integer i ) ;					(until C++14)
template < class Integer > constexpr double real( Integer i ) ;					(since C++14)

A,B) Additional overloads are provided for all integer and floating-point types, which are treated as complex numbers with zero imaginary part.

(since C++11)

Parameters

z	-	complex value
f	-	floating-point value
i	-	integer value

Return value

Notes

The additional overloads are not required to be provided exactly as (A,B). They only need to be sufficient to ensure that for their argument num:

• If num has a standard(until C++23) floating-point type T, then std::real(num) has the same effect as std:: real ( std::complex <T> (num) )
• Otherwise, if num has an integer type, then std::real(num) has the same effect as std:: real ( std::complex < double > (num) )

See also

real	accesses the real part of the complex number (public member function)
imag	returns the imaginary part (function template)
C documentation for creal