Assignment to std::complex number

[zender]

Hi,

Is it possible to a value separately to the real or imaginary
part of a complex number?

Any help appreciated,
Charlie

The following code shows that .real() and .imag() are not lvalues:

#include <iostream>
#include <complex>
int main()
{
std::complex<double> scalar;
scalar.real()=0.0;
}

zender@ashes:~/c++$ g++ -Wall -g -I${HOME}/include -o tst tst.cc
tst.cc: In function `int main()':
tst.cc:17: error: non-lvalue in assignment

 

[Mike Wahler]

Hi,

Is it possible to a value separately to the real or imaginary
part of a complex number?

I don't think so.

Any help appreciated,
Charlie

The following code shows that .real() and .imag() are not lvalues:

True. They return by value, not by reference.

#include <iostream>
#include <complex>
int main()
{
std::complex<double> scalar;
scalar.real()=0.0;

}

-Mike

 

[Jonathan Turkanis]

Hi,

Is it possible to a value separately to the real or imaginary
part of a complex number?

No, but there is support for adding this feature. See
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2004/n1589.html.

Jonathan

 

[Charlie Zender]

Thanks for the info!
Making real and imaginary component public and separatly assignable
would simplify many physics codes.

Charlie

 

[John Carson]

Hi,

Is it possible to a value separately to the real or imaginary
part of a complex number?

Any help appreciated,
Charlie

The following code shows that .real() and .imag() are not lvalues:

#include <iostream>
#include <complex>
int main()
{
std::complex<double> scalar;
scalar.real()=0.0;
}

For what it is worth VC++.Net offers the following "set function" as a
non-standard extension (presumably courtesy of the Dinkumware library that
it uses):

#include <iostream>
#include <complex>
int main()
{
std::complex<double> scalar;
scalar.real(0.0);
}