[Bug c++/22520] New: g++ treats object declaration as function declaration (rejects valid program)

["ccarena at cox dot net" <gcc-bugzilla at gcc dot gnu dot org>]

This is actually applicable to every version of g++ I have on my system, not
just 4.0.1. I am tempted to say I have it wrong, but the only difference between
the two object declarations is how a constant is expressed.

g++ treats these two object declarations as different:

  Angle angle1( Degrees(180.0    ));// an instance of Angle
  Angle angle2( Degrees(OneEighty));// declaration of a func??

where 

const double OneEighty = 180.0;

The following line is rejected because angle2 isn't an instance of Angle, but is
being treated as a function declaration, incorrectly, I think:

  angle1 += angle2;  // won't compile because angle2 isn't an Angle

The whole program follows:
///////////////////////////////////////////////start
const double OneEighty = 180.0;

struct Degrees
{
  double m_Degrees;

  Degrees( const double & degrees )
    :
    m_Degrees( degrees )
  {
  }
};

struct Angle
{
  double m_Degrees;

  Angle(const Degrees & degree)
    :
    m_Degrees( degree.m_Degrees )
  {
  }

  Angle & operator+=(const Angle & rhs)
  {
    m_Degrees += rhs.m_Degrees;
    
    return *this;
  }
};

void test(void)
{
  Angle angle1( Degrees(180.0    ));// an instance of Angle
  Angle angle2( Degrees(OneEighty));// declaration of a func??

  //
  // The following line fails  
  // on the compilers on my system of the following versions:
  // gcc version 2.96 20000731 (Red Hat Linux 7.3 2.96-126)
  // gcc version 3.3.3 20040412 (Red Hat Linux 3.3.3-7)
  // gcc version 3.4.0 (Red Hat Linux 3.4.0-1)
  // gcc version 4.0.0
  // gcc version 4.0.1 20050617 (prerelease)
  //
  angle1 += angle2;  // won't compile because angle2 isn't an Angle

  //
  // The following two types from typeid are not equal
  //
  //   printf("typeid(angle1).name() = \"%s\"\n", 
  // 	 typeid(angle1).name()
  // 	);

  //   printf("typeid(angle2).name() = \"%s\"\n", 
  // 	 typeid(angle2).name()
  // 	);
}
///////////////////////////////////////////// end

-- 
           Summary: g++ treats object declaration as function declaration
                    (rejects valid program)
           Product: gcc
           Version: 4.0.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ccarena at cox dot net
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22520