std::conj(std::complex)

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros(C++20)

Language support library

Concepts library(C++20)

Diagnostics library

Memory management library

Metaprogramming library(C++11)

General utilities library

Containers library

Iterators library

Ranges library(C++20)

Algorithms library

Strings library

Text processing library

Numerics library

Date and time library

Input/output library

Filesystem library(C++17)

Concurrency support library(C++11)

Execution control library(C++26)

Technical specifications

Symbols index

External libraries

 

Numerics library

Common mathematical functions
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)
Complex numbers
Numeric array (valarray)
Pseudo-random number generation
Bit manipulation(C++20)
Saturation arithmetic(C++26)
Factor operations
gcd (C++17)	lcm (C++17)
Interpolations
midpoint (C++20)	lerp (C++20)
Generic numeric operations
iota (C++11) ranges::iota (C++23) accumulate inner_product adjacent_difference    partial_sum	reduce (C++17) transform_reduce (C++17) inclusive_scan (C++17) exclusive_scan (C++17) transform_inclusive_scan (C++17) transform_exclusive_scan (C++17)
C-style checked integer arithmetic
ckd_add (C++26) ckd_sub (C++26)	ckd_mul (C++26)

 

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)
Exponential functions
log   log10   exp
Power functions
pow   sqrt
Trigonometric functions
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 > std::complex<T> conj(conststd::complex<T>& z );			(until C++20)
template<class T > constexprstd::complex<T> conj(conststd::complex<T>& z );			(since C++20)
Additional overloads(since C++11)
Defined in header <complex>
		(A)
std::complex<float>       conj(float f ); std::complex<double>      conj(double f ); std::complex<longdouble> conj(longdouble f );				(until C++20)
constexprstd::complex<float>       conj(float f ); constexprstd::complex<double>      conj(double f ); constexprstd::complex<longdouble> conj(longdouble f );				(since C++20) (until C++23)
template<class FloatingPoint > constexprstd::complex<FloatingPoint> conj( FloatingPoint f );				(since C++23)
			(B)
template<class Integer > constexprstd::complex<double> conj( Integer i );					(until C++20)
template<class Integer > constexprstd::complex<double> conj( Integer i );					(since C++20)

1) Computes the complex conjugate of z by reversing the sign of the imaginary part.

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

(since C++11)

Parameters

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

Return value

1) The complex conjugate of z.

A)std::complex(f).

B)std::complex<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::conj(num) has the same effect as std::conj(std::complex<T>(num)).
• Otherwise, if num has an integer type, then std::conj(num) has the same effect as std::conj(std::complex<double>(num)).

Example

Run this code

#include <complex>#include <iostream>   int main(){std::complex<double> z(1.0, 2.0);std::cout<<"The conjugate of "<< z <<" is "<< std::conj(z)<<'\n'<<"Their product is "<< z * std::conj(z)<<'\n';}

Output:

The conjugate of (1,2) is (1,-2) Their product is (5,0)

See also

abs(std::complex)	returns the magnitude of a complex number (function template)
norm	returns the squared magnitude (function template)
polar	constructs a complex number from magnitude and phase angle (function template)
C documentation for conj