Edit Question - KnowledgeHub

Title Body

In C++0x SFINAE rules have been simplified such that any invalid expression or type that occurs in the "immediate context" of deduction does not result in a compiler error but rather in deduction failure (SFINAE). My question is this: If I take the address of an overloaded function and it can not be resolved, is that failure in the immediate-context of deduction? (i.e is it a hard error or SFINAE if it can not be resolved)? Here is some sample code: struct X { // template<class T> T* foo(T,T); // lets not over-complicate things for now void foo(char); void foo(int); }; template<class U> struct S { template<int> struct size_map { typedef int type; }; // here is where we take the address of a possibly overloaded function template<class T> void f(T, typename size_map<sizeof(&U::foo)>::type* = 0); void f(...); }; int main() { S<X> s; // should this cause a compiler error because 'auto T = &X::foo' is invalid? s.f(3); } Gcc 4.5 states that this is a compiler error, and clang spits out an assertion violation. Here are some more related questions of interest: Does the FCD-C++0x clearly specify what should happen here? Are the compilers wrong in rejecting this code? Does the "immediate-context" of deduction need to be defined a little better? Thanks!

Tags (comma-separated) Cancel