On Thu, Sep 17, 2009 at 4:27 PM, Jeffrey Hellrung <jhellrung@ucla.edu> wrote:
Emil Dotchevski wrote:
On MSVC, the following correct code produces error C2896: 'void operator ||(T,void (__cdecl *)(tag<X>))' : cannot use function template 'void bar(tag<X>)' as a function argument.
struct foo { };
template <int X> struct tag { };
template <int X> void bar( tag<X> ) { }
template <class T,int X> void operator||(T, void(*)(tag<X>)) { }
int main() { foo()||bar<1>; }
My goal is to have an operator|| overload that deduces tag<X> implicitly, but without using parenthesis, that is, foo()||bar<1>() wouldn't be satisfactory. Doesn't seem possible, but still I decided to ask. Any ideas?
What about statically initialized pod objects, like the placeholder arguments in phoenix or lambda?
I guess that only works if you have a (reasonably) bounded set from which X can come from...
You mean something like _1, _2, etc? Yes that could work but it's not ideal. Also, I found some other curiosities, like the fact that this declaration for op|| works: template <class T> void operator||(T, void(*)(tag<1>)) { } Presumably, I could provide K overloads instead of using the X template argument. That's silly, but it has the same limitations of the _1, _2 approach and has the benefit of not being silly on other compilers. I've also found that my original code works fine if I overload the comma operator instead of ||. Go figure... Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode