CWG2664 Deduction failure in CTAD for alias templates

Author: burblebee

source/overloading.tex

@@ -1351,6 +1351,8 @@
 according to the process in \ref{temp.deduct.type}
 with the exception that deduction does not fail
 if not all template arguments are deduced.
+If deduction fails for another reason,
+proceed with an empty set of deduced template arguments.
 Let \tcode{g} denote the result of substituting
 these deductions into \tcode{f}.
 If substitution succeeds,