[Bug c++/49803] New: [C++0x] erroneous variant-member initialization in a union containing an anonymous struct

[fuchsia.groan at virgin dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49803

           Summary: [C++0x] erroneous variant-member initialization in a
                    union containing an anonymous struct
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: fuchsia.gr...@virgin.net


/* The output of this code should be 'Y'.  But define SHOW_BUG and it becomes
X: */
#define SHOW_BUG
#include <cstdio>
struct X
{
    X() : m_value {'X'} {}

    char m_value;
};


union Y
{
    // N3291=11-0061 12.6.2/8 says no initialization of
    // of other variant members (i.e. m_x) should
    // be performed.
    Y( char c )
        : m_char1{ c }

        { }

#ifdef SHOW_BUG
    struct
    {
#endif    
        char m_char1;
#ifdef SHOW_BUG
    };
#endif

    X    m_x;
};

int main()
{
    Y y ( 'Y' ); 

    printf( "%c\n", y.m_char1 ); // expected 'Y', get 'X'...
    return 0;
}