http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59165
Bug ID: 59165
Summary: gcc looks up begin(), end() for for-range loops for
ints in namespace std
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: thakis at chromium dot org
This compiles, but shouldn't:
$ cat gcc4.8bug.cc
// builds with gcc4.8, but shouldn't
namespace std {
int* begin(int i) { return (int*)0; }
int* end(int i) { return (int*)0; }
}
int main() {
for (int a : 10) { }
}
$ gcc-4.8.1 -c gcc4.8bug.cc -std=c++11
# works
The standard says that begin() and end() for foreach loops should be looked up
in the associated namespace of the type of the expression (6.5.4p1)
"""otherwise, begin-expr and end-expr are begin(__range) and end(__range),
respectively, where begin and end are looked up in the associated namespaces
(3.4.2). [ Note: Ordinary unqualified lookup (3.4.1) is not performed. — end
note ]"""
10 has type int, which is a fundamental type, and hence doesn't have an
associated namespace. So this shouldn't compile. (It doesn't compile in clang.)
$ gcc-4.8.1 --version
gcc-4.8.1 (GCC) 4.8.1
Copyright (C) 2013 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
