std::real(std::complex)

 

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std::complex

Member functions
complex::complex complex::operator= complex::real complex::imag	complex::operator+=complex::operator-=complex::operator*=complex::operator/=
Non-member functions
operator+operator- operator+operator-operator*operator/ operator==operator!= (until C++20)   operator<<operator>> get(std::complex) (C++26)	real imag abs arg norm conj proj (C++11) polar operator""ioperator""ifoperator""il (C++14)(C++14)(C++14)
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log   log10   exp
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pow   sqrt
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sin   cos tan asin (C++11) acos (C++11) atan (C++11)
Hyperbolic functions
sinh   cosh tanh asinh (C++11) acosh (C++11) atanh (C++11)
Helper types
tuple_size<std::complex> (C++26)
tuple_element<std::complex> (C++26)

 

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)

1) Returns the real part of the complex number z, i.e. z.real().

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

1) The real part of z.

A) f.

B) static_cast<double>(i).

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