[cfe-dev] default arguments cannot be added to an out-of-line definition of a member of a class template

[Jack Howarth]

   While trying to compile ccp4 with clang, I ran into the following error in the test case...

------------- outofline.cpp --------------------
template <typename realnum>
class covar_matrix
{
  public:

        void SetZeroRows(int,int,int,int,int,int);      // specifies the order numbers of rows(=columns) for which the covariances should be 0.

  private:

};



// defines zero rows. If the first argument is negative, resets all no non-zero.
template <typename realnum>
void covar_matrix<realnum>::SetZeroRows( int r1=-1, int r2=-1, int r3=-1, int r4=-1, int r5=-1, int r6=-1 )
{
  int r[6] = {r1,r2,r3,r4,r5,r6};
  int i=0;
}

------------------------------------------------

[MacPro:~] howarth% clang -c outofline.cpp
outofline.cpp:16:46: error: default arguments cannot be added to an out-of-line definition of a member of a class template
void covar_matrix<realnum>::SetZeroRows( int r1=-1, int r2=-1, int r3=-1, int r4=-1, int r5=-1, int r6=-1 )
                                             ^  ~~
outofline.cpp:16:57: error: default arguments cannot be added to an out-of-line definition of a member of a class template
void covar_matrix<realnum>::SetZeroRows( int r1=-1, int r2=-1, int r3=-1, int r4=-1, int r5=-1, int r6=-1 )
                                                        ^  ~~
outofline.cpp:16:68: error: default arguments cannot be added to an out-of-line definition of a member of a class template
void covar_matrix<realnum>::SetZeroRows( int r1=-1, int r2=-1, int r3=-1, int r4=-1, int r5=-1, int r6=-1 )
                                                                   ^  ~~
outofline.cpp:16:79: error: default arguments cannot be added to an out-of-line definition of a member of a class template
void covar_matrix<realnum>::SetZeroRows( int r1=-1, int r2=-1, int r3=-1, int r4=-1, int r5=-1, int r6=-1 )
                                                                              ^  ~~
outofline.cpp:16:90: error: default arguments cannot be added to an out-of-line definition of a member of a class template
void covar_matrix<realnum>::SetZeroRows( int r1=-1, int r2=-1, int r3=-1, int r4=-1, int r5=-1, int r6=-1 )
                                                                                         ^  ~~
outofline.cpp:16:101: error: default arguments cannot be added to an out-of-line definition of a member of a class template
void covar_matrix<realnum>::SetZeroRows( int r1=-1, int r2=-1, int r3=-1, int r4=-1, int r5=-1, int r6=-1 )
                                                                                                    ^  ~~
6 errors generated.

I assume this isn't a bug in clang. If so, what is the proper solution? Is it this change?

--------------- outofline2.cpp ---------------
template <typename realnum>
class covar_matrix
{
  public:

        void SetZeroRows(int,int,int,int,int,int);      // specifies the order numbers of rows(=columns) for which the covariances should be 0.

  private:

};



// defines zero rows. If the first argument is negative, resets all no non-zero.
template <typename realnum>
void covar_matrix<realnum>::SetZeroRows( int r1, int r2, int r3, int r4, int r5, int r6 )
{
  int r[6] = {r1,r2,r3,r4,r5,r6};
  int i=0;
  r1=-1;
  r2=-1;
  r3=-1;
  r4=-1;
  r5=-1;
  r6=-1;
}
----------------------------------------------
This compiles without complaint in clang. Thanks in advance for any clarifications.
             Jack