[Bug c++/58707] New: [C++11] A greater-than operator in square brackets should not end a template argument list

["tuomas.tynkkynen at iki dot fi" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58707

            Bug ID: 58707
           Summary: [C++11] A greater-than operator in square brackets
                    should not end a template argument list
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tuomas.tynkkynen at iki dot fi

Created attachment 30993
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30993&action=edit
The failing code snippet

The following code snippet does not compile on latest GCC trunk:

template<int i> class TC { };
constexpr int foo[] = { 42, };
TC<foo[0 > 1]> bar;

Actual result:

tmtynkky@e42-7:/tmp$ /dos/gcc-trunk/bin/gcc -xc++ -std=c++11 -pedantic -c -o
/dev/null bracket.cpp 
bracket.cpp:3:10: error: template argument 1 is invalid
 TC<foo[0 > 1]> bar;
          ^
bracket.cpp:3:12: error: expected unqualified-id before numeric constant
 TC<foo[0 > 1]> bar;
            ^

The '>' seems to get parsed as the ending delimiter of the template argument
list, even though it shouldn't since it is nested inside a pair of square
brackets. Clang++ 3.3 correctly accepts this snippet.

(originally discussed on
http://forum.cppgm.org/question/2286/inside-square-brackets-terminates-a-template-argument-list/)

Version information:

gcc version 4.9.0 20131011 (experimental) [trunk revision 203401] (GCC) 
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-trunk-source/gcc/configure --enable
languages=c,c++,fortran --enable-checking=release --disable-libmudflap
--disable libstdcxx-pch --enable-libgomp --enable-lto --enable-gold
--with-plugin ld=/usr/bin/gold --with-cloog-include=/usr/include-cloog
--with-cloog lib=/usr/lib64 --prefix=/usr/local/gcc-trunk