std::complex::operator=

From cppreference.com
< cpp‎ | numeric‎ | complex
complex<T>& operator=( const T& x );
(1)
template< class X >
complex<T>& operator=( const complex<X>& cx );
(2)

Assigns new values to the contents.

1) Assigns x to the real part of the complex number. Imaginary part is set to zero.
2) Assigns cx.real() and cx.imag() to the real and the imaginary parts of the complex number respectively.

Parameters

x - value to assign
cx - complex value to assign

Return value

*this

See also

constructs a complex number
(public member function)
A std::complex literal representing pure imaginary number
(function)