On Sat, May 28, 2011 at 1:31 PM, Matt Calabrese <rivorus@gmail.com> wrote:
On Sat, May 28, 2011 at 3:23 PM, Jeffrey Lee Hellrung, Jr. < jeffrey.hellrung@gmail.com> wrote:
Here's a trial attempt at an implementation of the macro (warning: not tested):
I haven't looked at the implementation in depth, but if I recall correctly, C++0x explicit conversions to bool are not quite the same as a safe-bool conversion (explicit conversions still generally require explicit casts, correct me if I'm wrong). Because of this, I do not believe it would be a good idea for such a macro to automatically use explicit conversion operators when available as it could result in user code that compiles in 03 but fails to compile in 0x.
You make a good point, and if all C++0x compilers generate equally efficient code for each technique, then we should just stick with the slightly-more-complicated pointer-to-member hack. Perhaps it would prudent to provide a macro flag which signals to use explicit bool conversion operators when available, for (the rare?) cases when the compiler generates more efficient code for the explicit bool conversion operator, and users desire such efficiency. - Jeff