like a copy constructor to the overload set, just ignore it. This
ensures that we don't try to use such a constructor as a copy
constructor *without* triggering diagnostics at the point of
declaration.
Note that we *do* diagnose such copy constructors when explicitly
written by the user (e.g., as an explicit specialization).
llvm-svn: 88733
by distinguishing between substitution that occurs for template
argument deduction vs. explicitly-specifiad template arguments. This
is used both to improve diagnostics and to make sure we only provide
SFINAE in those cases where SFINAE should apply.
In addition, deal with the sticky issue where SFINAE only considers
substitution of template arguments into the *type* of a function
template; we need to issue hard errors beyond this point, as
test/SemaTemplate/operator-template.cpp illustrates.
llvm-svn: 74651