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operator+,-,*,/ (std::complex)

From cppreference.com
< cpp‎ | numeric‎ | complex
 
 
 
 
(1)
template<class T >

std::complex<T> operator+(conststd::complex<T>& lhs,

                           conststd::complex<T>& rhs );
(until C++20)
template<class T >

constexprstd::complex<T> operator+(conststd::complex<T>& lhs,

                                     conststd::complex<T>& rhs );
(since C++20)
(2)
template<class T >

std::complex<T> operator+(conststd::complex<T>& lhs,

                           const T& rhs );
(until C++20)
template<class T >

constexprstd::complex<T> operator+(conststd::complex<T>& lhs,

                                     const T& rhs );
(since C++20)
(3)
template<class T >

std::complex<T> operator+(const T& lhs,

                           conststd::complex<T>& rhs );
(until C++20)
template<class T >

constexprstd::complex<T> operator+(const T& lhs,

                                     conststd::complex<T>& rhs );
(since C++20)
(4)
template<class T >

std::complex<T> operator-(conststd::complex<T>& lhs,

                           conststd::complex<T>& rhs );
(until C++20)
template<class T >

constexprstd::complex<T> operator-(conststd::complex<T>& lhs,

                                     conststd::complex<T>& rhs );
(since C++20)
(5)
template<class T >

std::complex<T> operator-(conststd::complex<T>& lhs,

                           const T& rhs );
(until C++20)
template<class T >

constexprstd::complex<T> operator-(conststd::complex<T>& lhs,

                                     const T& rhs );
(since C++20)
(6)
template<class T >

std::complex<T> operator-(const T& lhs,

                           conststd::complex<T>& rhs );
(until C++20)
template<class T >

constexprstd::complex<T> operator-(const T& lhs,

                                     conststd::complex<T>& rhs );
(since C++20)
(7)
template<class T >

std::complex<T> operator*(conststd::complex<T>& lhs,

                           conststd::complex<T>& rhs );
(until C++20)
template<class T >

constexprstd::complex<T> operator*(conststd::complex<T>& lhs,

                                     conststd::complex<T>& rhs );
(since C++20)
(8)
template<class T >

std::complex<T> operator*(conststd::complex<T>& lhs,

                           const T& rhs );
(until C++20)
template<class T >

constexprstd::complex<T> operator*(conststd::complex<T>& lhs,

                                     const T& rhs );
(since C++20)
(9)
template<class T >

std::complex<T> operator*(const T& lhs,

                           conststd::complex<T>& rhs );
(until C++20)
template<class T >

constexprstd::complex<T> operator*(const T& lhs,

                                     conststd::complex<T>& rhs );
(since C++20)
(10)
template<class T >

std::complex<T> operator/(conststd::complex<T>& lhs,

                           conststd::complex<T>& rhs );
(until C++20)
template<class T >

constexprstd::complex<T> operator/(conststd::complex<T>& lhs,

                                     conststd::complex<T>& rhs );
(since C++20)
(11)
template<class T >

std::complex<T> operator/(conststd::complex<T>& lhs,

                           const T& rhs );
(until C++20)
template<class T >

constexprstd::complex<T> operator/(conststd::complex<T>& lhs,

                                     const T& rhs );
(since C++20)
(12)
template<class T >

std::complex<T> operator/(const T& lhs,

                           conststd::complex<T>& rhs );
(until C++20)
template<class T >

constexprstd::complex<T> operator/(const T& lhs,

                                     conststd::complex<T>& rhs );
(since C++20)

Implements the binary operators for complex arithmetic and for mixed complex/scalar arithmetic. Scalar arguments are treated as complex numbers with the real part equal to the argument and the imaginary part set to zero.

1-3) Returns the sum of its arguments.
4-6) Returns the result of subtracting rhs from lhs.
7-9) Multiplies its arguments.
10-12) Divides lhs by rhs.

Contents

[edit]Parameters

lhs, rhs - the arguments: either both complex numbers or one complex and one scalar of matching type (float, double, longdouble)

[edit]Return value

1-3)std::complex<T>(lhs)+= rhs
4-6)std::complex<T>(lhs)-= rhs
7-9)std::complex<T>(lhs)*= rhs
10-12)std::complex<T>(lhs)/= rhs

[edit]Notes

Because template argument deduction does not consider implicit conversions, these operators cannot be used for mixed integer/complex arithmetic. In all cases, the scalar must have the same type as the underlying type of the complex number.

The GCC flag "-fcx-limited-range" (included by "-ffast-math") changes the behavior of complex multiply/division by removing checks for floating point edge cases. This impacts loop vectorization.

[edit]Example

#include <complex>#include <iostream>   int main(){std::complex<double> c2(2.0, 0.0);std::complex<double> ci(0.0, 1.0);   std::cout<< ci <<" + "<< c2 <<" = "<< ci + c2 <<'\n'<< ci <<" * "<< ci <<" = "<< ci * ci <<'\n'<< ci <<" + "<< c2 <<" / "<< ci <<" = "<< ci + c2 / ci <<'\n'<<1<<" / "<< ci <<" = "<<1.0/ ci <<'\n';   // std::cout << 1.0f / ci; // compile error// std::cout << 1 / ci; // compile error}

Output:

(0,1) + (2,0) = (2,1) (0,1) * (0,1) = (-1,0) (0,1) + (2,0) / (0,1) = (0,-1) 1 / (0,1) = (0,-1)

[edit]See also

compound assignment of two complex numbers or a complex and a scalar
(public member function)[edit]
applies unary operators to complex numbers
(function template)[edit]
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