std::real(std::complex)
From cppreference.com
C++
Feature test macros (C++20)
Concepts library (C++20)
Metaprogramming library (C++11)
Ranges library (C++20)
Filesystem library (C++17)
Concurrency support library (C++11)
Execution control library (C++26)
Numerics library
Mathematical special functions (C++17)
Mathematical constants (C++20)
Basic linear algebra algorithms (C++26)
Data-parallel types (SIMD) (C++26)
Floating-point environment (C++11)
Bit manipulation (C++20)
Saturation arithmetic (C++26)
(C++17)
(C++17)
(C++17)
(C++17)
(C++17)
(C++17)
std::complex
(until C++20)
(C++26)
(C++26)
(C++26)
Defined in header
<complex>
(1)
template< class T >
T real( const std::complex <T>& z );
(until C++14)
T real( const std::complex <T>& z );
template< class T >
constexpr T real( const std::complex <T>& z );
(since C++14)
constexpr T real( const std::complex <T>& z );
Additional overloads (since C++11)
Defined in header
<complex>
(A)
float real( float f );
(until C++14)
double real( double f );
constexpr float real( float f );
(since C++14) constexpr double real( double f );
(until C++23)
template< class FloatingPoint >
constexpr FloatingPoint real( FloatingPoint f );
(since C++23)
constexpr FloatingPoint real( FloatingPoint f );
(B)
template< class Integer >
double real( Integer i );
(until C++14)
double real( Integer i );
template< class Integer >
constexpr double real( Integer i );
(since C++14)
constexpr double real( Integer i );
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)Contents
[edit] Parameters
z
-
complex value
f
-
floating-point value
i
-
integer value
[edit] Return value
1) The real part of z.
A) f.
B) static_cast<double>(i).
[edit] 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)).
[edit] See also
C documentation for creal