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* [Bug c++/46162] New: Invalid SFINAE with static member function/variable
@ 2010-10-25  2:32 greg.r.rogers at gmail dot com
  2010-10-26  9:13 ` [Bug c++/46162] " paolo.carlini at oracle dot com
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: greg.r.rogers at gmail dot com @ 2010-10-25  2:32 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46162

           Summary: Invalid SFINAE with static member function/variable
           Product: gcc
           Version: 4.5.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: greg.r.rogers@gmail.com


gcc rejects the following valid code, which compiles under clang, Comeau, and
MSVC++. Expected output is "0 0". I am using gcc 4.5.1, I have not tried it on
older versions.


grogers@gazelle ~/junk $ cat junk.cpp 
#include <iostream>

struct small_type { char dummy; };
struct large_type { char dummy[2]; };

template<class T>
struct has_foo_member_variable
{
    template<int T::*> struct tester;
    template<class U> static small_type has_foo(tester<&U::foo> *);
    template<class U> static large_type has_foo(...);
    static const bool value = (sizeof(has_foo<T>(0)) == sizeof(small_type));
};

struct A
{
    static int foo()
    {
        return 0;
    }
};

struct B
{
    static int foo;
};

int main()
{
    std::cout << has_foo_member_variable<A>::value << ' '
        << has_foo_member_variable<B>::value << '\n';
}
grogers@gazelle ~/junk $ g++ junk.cpp 
junk.cpp: In instantiation of ‘const bool has_foo_member_variable<A>::value’:
junk.cpp:30:46:   instantiated from here
junk.cpp:12:75: error: ‘A::foo’ is not a valid template argument for type ‘int
A::*’
junk.cpp:12:75: error: it must be a pointer-to-member of the form `&X::Y'
junk.cpp: In instantiation of ‘const bool has_foo_member_variable<B>::value’:
junk.cpp:31:40:   instantiated from here
junk.cpp:12:75: error: ‘& B::foo’ is not a valid template argument for type
‘int B::*’
junk.cpp:12:75: error: it must be a pointer-to-member of the form `&X::Y'
grogers@gazelle ~/junk $ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/i686-pc-linux-gnu/4.5.1/lto-wrapper
Target: i686-pc-linux-gnu
Configured with: ../configure --prefix=/usr
--enable-languages=c,c++,fortran,objc,obj-c++,ada --enable-shared
--enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu
--enable-gnu-unique-object --enable-lto --enable-plugin --disable-multilib
--disable-libstdcxx-pch --with-system-zlib --with-ppl --with-cloog
--libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man
--infodir=/usr/share/info
Thread model: posix
gcc version 4.5.1 (GCC) 
grogers@gazelle ~/junk $ uname -a
Linux gazelle 2.6.35-ARCH #1 SMP PREEMPT Fri Aug 27 16:22:18 UTC 2010 i686 AMD
Phenom(tm) 9950 Quad-Core Processor AuthenticAMD GNU/Linux


^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2010-11-02 12:59 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2010-10-25  2:32 [Bug c++/46162] New: Invalid SFINAE with static member function/variable greg.r.rogers at gmail dot com
2010-10-26  9:13 ` [Bug c++/46162] " paolo.carlini at oracle dot com
2010-10-28 14:48 ` dodji at gcc dot gnu.org
2010-11-02 12:59 ` dodji at gcc dot gnu.org

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