[Bug c++/92434] noexcept couldn't be deduced in function template

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92434

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
To match clang we could use 

--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -21470,6 +21470,12 @@ uses_deducible_template_parms (tree type)
       for (; parm; parm = TREE_CHAIN (parm))
    if (uses_deducible_template_parms (TREE_VALUE (parm)))
      return true;
+      if (flag_noexcept_type)
+   {
+     tree spec = TYPE_RAISES_EXCEPTIONS (type);
+     if (deducible_expression (TREE_PURPOSE (spec)))
+       return true;
+   }
     }

   return false;