John Maddock ha escrito:
Hmmm, the interesting thing is, I'm having a hard time convincing myself that this code is legal, I'm cc'ing our friendly IBM compiler expert in case he can shed light on this.
Consider the code again:
#include <algorithm>
template<typename T> struct foo { T t; foo():t(0){} void swap(foo& x) { using std::swap; swap(t,x.t); } };
template<typename T> void swap(foo<T>& x,foo<T>& y) { x.swap(y); }
int main() { foo<int> x,y; x.swap(y); }
In foo::swap the local declaration of the member function "swap" hides any occurances of swap in the outer scope, and the using declaration behaves "as if" std::swap were imported into the *enclosing namespace*, which would still be hidden... and yet I can't believe that this simple idiom isn't actually legal ! :-) And indeed all the other compilers I tested do compile this OK.
Ouch, didn't think about name hiding... this is why I love C++ :-/ Now I don't know either whether the code is legal or not. Anyway, if I changed foo::swap to foo::swop the code would be undoubtedly legal then, right? Noel, would you please try the attached variation? Joaquín M López Muñoz Telefónica, Investigación y Desarrollo