[Bug libstdc++/48760] [4.6 / 4.7 Regression (?)] std::complex constructor buggy in the face of NaN's

[joseph at codesourcery dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48760

--- Comment #17 from joseph at codesourcery dot com <joseph at codesourcery dot com> 2011-04-26 15:03:49 UTC ---
As far as I can see, the main (only?) use of imaginary types is for this 
issue of constructing complex values.  In addition, you need to define for 
each target the ABI for argument passing and return of imaginary types 
(and in particular how _Imaginary float is passed in variable arguments - 
it is *not* promoted to _Imaginary double, whereas float is promoted to 
double in variable arguments at the C language level before the ABI comes 
into play, so whereas targets don't need to allow for unpromoted float in 
variable arguments they do need to allow for unpromoted _Imaginary float).  
But, given that, it would indeed be nice to support imaginary types.