Understand signature of opOpAssign in std/complex.d

[René Heldmaier]

On Saturday, 9 November 2019 at 13:26:12 UTC, Adam D. Ruppe wrote:
> That's checking the if the template argument C is a case of 
> Complex!R, while at the same time declaring a symbol R to hold 
> the inner type.

I got it. Thank you very much ;)