Is there a way to do inplace conjugation? I understand I could make a complex<float> j(1.0f, -1.0f) and multiply my vector by it with *=, but that does unnecessary multiplications on the real part of the array.

The following will work in-place:
A = A.conjugate();

ggael wrote:The following will work in-place:
A = A.conjugate();

Oh, I had assumed it wouldn't. Thanks!

that's the beauty of expression templates!