This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 115d. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
2024-10-26
I get the following error diagnostic [from the EDG front end]:
line 8: error: function template "example<T>::foo<R,A>(A)" has already been declared R foo(const A); ^when compiling this piece of code:
struct example { template<class R, class A> // 1-st member template R foo(A); template<class R, class A> // 2-nd member template const R foo(A&); template<class R, class A> // 3-d member template R foo(const A); }; /*template<> template<> int example<char>::foo(int&);*/ int main() { int (example<char>::* pf)(int&) = &example<char>::foo; }
The implementation complains that
template<class R, class A> // 1-st member template R foo(A); template<class R, class A> // 3-d member template R foo(const A);cannot be overloaded and I don't see any reason for it since it is function template specializations that are treated like ordinary non-template functions, meaning that the transformation of a parameter-declaration-clause into the corresponding parameter-type-list is applied to specializations (when determining its type) and not to function templates.
What makes me think so is the contents of 13.7.7.2 [temp.over.link] and the following sentence from 13.10.3.2 [temp.deduct.call] "If P is a cv-qualified type, the top level cv-qualifiers of P are ignored for type deduction". If the transformation was to be applied to function templates, then there would be no reason for having that sentence in 13.10.3.2 [temp.deduct.call].
13.10.3.3 [temp.deduct.funcaddr], which my example is based upon, says nothing about ignoring the top level cv-qualifiers of the function parameters of the function template whose address is being taken.
As a result, I expect that template argument deduction will fail for the 2-nd and 3-d member templates and the 1-st one will be used for the instantiation of the specialization.