on Sun Sep 16 2012, Lorenzo Caminiti <lorcaminiti-AT-gmail.com> wrote:
On Sun, Sep 16, 2012 at 6:27 PM, Dave Abrahams <dave@boostpro.com> wrote:
on Tue Sep 04 2012, Lorenzo Caminiti <lorcaminiti-AT-gmail.com> wrote:
Just to consider all alternatives, we could also do this:
CONTRACT_FUNCTION( template( typename To, typename From ) if( // used with enable_if in the declaration part is_convertible<From, To>::value, is_convertible<To, From>::value )
+1 for "if." Andrzej's "enable_if" suggestion is nice and more explicit too, but there's no syntax highlighting bonus. I'm torn.
requires( // included in the function body
The fact that this is "included in the function body" is irrelevant I think. I guess the real point you're trying to make is that it generates hard errors at acompile time when violated. That suggests something like "asserts" instead of "requires."
Then I think "check" for hard errors and "requires" for SFINAE is a good choice (requires better than if or enable_if for SFINAE I think...).
I don't see what justifies any of those conclusions. Neither "check" nor "requires" particularly implies hard errors or SFINAE. enable_if does, even if you don't know what SFINAE is. -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost