Hi! The casts added for the C++17 direct enum initialization IMNSHO shouldn't trigger -Wuseless-cast warnings.
Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? 2017-09-29 Jakub Jelinek <ja...@redhat.com> PR c++/82299 * decl.c (reshape_init): Suppress warn_useless_cast for direct enum init. * typeck.c (convert_for_assignment): Likewise. * g++.dg/cpp0x/pr82299.C: New test. --- gcc/cp/decl.c.jj 2017-09-29 11:21:55.000000000 +0200 +++ gcc/cp/decl.c 2017-09-29 15:19:02.549548102 +0200 @@ -6053,7 +6053,10 @@ reshape_init (tree type, tree init, tsub tree elt = CONSTRUCTOR_ELT (init, 0)->value; type = cv_unqualified (type); if (check_narrowing (ENUM_UNDERLYING_TYPE (type), elt, complain)) - return cp_build_c_cast (type, elt, tf_warning_or_error); + { + warning_sentinel w (warn_useless_cast); + return cp_build_c_cast (type, elt, tf_warning_or_error); + } else return error_mark_node; } --- gcc/cp/typeck.c.jj 2017-09-29 09:07:33.000000000 +0200 +++ gcc/cp/typeck.c 2017-09-29 15:21:17.770926572 +0200 @@ -8527,7 +8527,10 @@ convert_for_assignment (tree type, tree { tree elt = CONSTRUCTOR_ELT (rhs, 0)->value; if (check_narrowing (ENUM_UNDERLYING_TYPE (type), elt, complain)) - rhs = cp_build_c_cast (type, elt, complain); + { + warning_sentinel w (warn_useless_cast); + rhs = cp_build_c_cast (type, elt, complain); + } else rhs = error_mark_node; } --- gcc/testsuite/g++.dg/cpp0x/pr82299.C.jj 2017-09-29 15:24:18.909754416 +0200 +++ gcc/testsuite/g++.dg/cpp0x/pr82299.C 2017-09-29 15:29:15.589237065 +0200 @@ -0,0 +1,9 @@ +// PR c++/82299 +// { dg-do compile { target c++11 } } +// { dg-options "-Wuseless-cast" } + +enum Enum : char { A = 0, B = 1 }; + +struct S { + Enum e { Enum::A }; // { dg-bogus "useless cast to type" } +}; Jakub