How to use _Generic with bit-fields

[Joseph Myers]

On Fri, 19 Feb 2016, Wink Saville wrote:

> And I've tried to use _Generic to print the type of a bit field but
> the compiler fails with:

Indeed, bit-field types cannot match any type name, only default.  The 
only conversions applied to the controlling expression are those involved 
in lvalue to rvalue conversion (at least, that's what's currently 
implemented, and is the current direction on DR#481).  In particular, the 
integer promotions (which would convert this bit-field to int) are not 
applied.

You can of course use unary + (or various other constructs depending on 
the set of possible types) to cause some promotions.

-- 
Joseph S. Myers
joseph@codesourcery.com