http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54526
Bug #: 54526
Summary: <:: is incorrectly treated as digraph <: followed by
colon
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: ts...@mail.ru
g++ 4.8.0 20120826 (experimental) fails to compile the following well-defined
code:
template <class T>
struct X {};
struct A {};
int main()
{
X<::A> x; // error: ‘<::’ cannot begin a template-argument list
}
According to C++11 - 2.5 p3, bullet 2:
If the input stream has been parsed into preprocessing tokens up to a given
character:
... if the next three characters are <:: and the subsequent character is
neither : nor >, the < is treated as a preprocessor token by itself and not as
the first character of the alternative token <:.
Compiler version info:
Target: i686-pc-linux-gnu
Configured with: .../configure --prefix=.../target --enable-languages=c,c++
Thread model: posix
gcc version 4.8.0 20120826 (experimental) (GCC)
Command line:
g++ test.cpp -std=c++11 -pedantic-errors
Diagnostic message:
test.cpp: In function ‘int main()’:
test.cpp:8:10: error: ‘<::’ cannot begin a template-argument list
[-fpermissive]
X<::A> x;
^
test.cpp:8:10: note: ‘<:’ is an alternate spelling for ‘[’. Insert whitespace
between ‘<’ and ‘::’
test.cpp:8:10: note: (if you use ‘-fpermissive’ G++ will accept your code)
