https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77812
Bug ID: 77812
Summary: incorrectly rejects valid C++ code that uses enum in
template instantiation
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: su at cs dot ucdavis.edu
Target Milestone: ---
It affects 4.7.x and later, and is a regression from 4.6.x.
Both Clang and ICC also accept the code.
The code is accepted if a struct is used for template instantiation instead
(see small2.cpp).
$ g++-trunk -v
Using built-in specs.
COLLECT_GCC=g++-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/7.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto
--prefix=/usr/local/gcc-trunk --disable-bootstrap
Thread model: posix
gcc version 7.0.0 20160930 (experimental) [trunk revision 240688] (GCC)
$
$ g++-4.6 -c small1.cpp
$ clang++-3.8 -c small1.cpp
$
$ g++-trunk -c small1.cpp
small1.cpp: In function ‘void f()’:
small1.cpp:5:12: error: use of enum ‘f’ without previous declaration
f < enum f > ();
^
$
$ g++-trunk -c small2.cpp
$
$ cat small1.cpp
enum f { R, G, B };
template < typename > void f ()
{
f < enum f > ();
}
$
$ cat small2.cpp
struct f {};
template < typename > void f ()
{
f < struct f > ();
}
$
