regression on 2.8.1: type conv. overld problem

[Stefan Schwarzer <sts at ica1 dot uni-stuttgart dot de>]

// The following code demonstrates a bug (in the overload resolution?). 
// In the presence of the const version
// of the user supplied type conversion to double *, egcs does not compile the appended code.
// (This is a regression against gcc-2.8.1 which compiles the code without complaints) 
//
// Without the const version of operator double *, things work as expected. 
// With KCC or cxx, the code compiles in both cases without problems.
//
// I do not include preprocessor output, because it is basically identical to the source.
// 
// Reading specs from /local/egcs-1.1.1/lib/gcc-lib/sparc-sun-solaris2.5.1/egcs-2.91.60/specs
// gcc version egcs-2.91.60 19981201 (egcs-1.1.1 release)
// (name sqangling compiled in)
//
// The bug is still present in the 1.1.2 pre1 (with squangling)
//
// 20:55 boa_sts:~/bugs/gnu> g++ c_arr.cc 
// c_arr.cc: In function `int main()':
// c_arr.cc:14: no match for `CArray & + int'
//
//

class CArray 
{
public:
  operator double* (){ return a; }
  // works if we comment this line:
  operator double* () const { return const_cast<double *>(a); }
private:   
  double      a[1];   
};

int main(){
  CArray  a;
  double *pa = a + 1;
}