bfb46e486d
The key changes in this patch are: 1. Remove the zero-argument overload in mem_fn. A member function must always be invoked with at least one argument, the class instance. The zero-argument operator()() in mem_fn would cause mem_fn to fail to compile when because the call to '__invoke(pm)' is not well formed. 2. Prevent evaluation of '__apply_cv<Tp, Ret>' when 'Ret' is a function type. 'Ret' is a function type whenever 'Ret Tp::*' is a pointer to member function. Attempting to add cv and ref qualifiers to a function type can cause a hard compile error. 3. Remove the dummy overload __invoke(Rp Tp::*). It was present to help work around #1. It will be replaced with a different '__invoke' overload that represents a bad call to invoke. After applying this patch the test func.wrap.func.inv/invoke.pass.cpp now passes. git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@243370 91177308-0d34-0410-b5e6-96231b3b80d8