Dear C++ experts:

I am experiencing a problem when I am constructing a derived class. I think
I have narrowed down the problem.

The code segment and two scripts of compilation under AT&T C++ V3.0 and
GCC 2.2.2 are appended in the end of this message.

The problem lies in the constructor of the derived class D:

    D(int s) { if(s>0) B<int>(s); else B<int>(-s); }

A simple change such as

 D(int s) : B<int>((s>0)? s: -s) {}

or
    D(int s) : B<int>(s) { if(s<0) _s=-s; }

will make the problem go away.

But I would very much like to know what's the problem with the constructor
in the original code.

Would you please help?

/************Code Segment Follows *********************/
/************ strange.h ***Cut Here *******************/

   template<class S>
   class B
   {
      S _s;
   public:
      B(S s) : _s(s) {}
     ~B() {}
   };


   class D : public B<int>
   {
   public:
      D(int s) { if(s>0) B<int>(s); else B<int>(-s); }
     ~D() {}
   };
/********************************************************/
/************ strange.C *********************************/

   #include "strange.h"

   main()
   {
      D x(-3);
   }
/*********************************************************/

/*********************************************************/
Script of compilation under AT&T C++ V3.0

Script started on Sun Dec  6 16:19:57 1992
math[/u3/xjzhu/postnews][29] CC strange.C
CC  strange.C:
"./strange.h", line 13: error:  argument  1 of type int  expected for  B <int >::B__pt__2_i()
"./strange.h", line 15: warning: result of  constructor call expression not used
"./strange.h", line 15: warning: result of  constructor call expression not used
"./strange.h", line 13: sorry, cannot recover from earlier errors
2 errors
math[/u3/xjzhu/postnews][30] exit
script done on Sun Dec  6 16:20:31 1992
/***********************************************************/

/***********************************************************/
Script of Compilation under GCC 2.2.2

Script started on Sun Dec  6 16:27:08 1992
g++ strange.C
strange.h: In method `D::D (int)':
In file included from strange.C:1:
strange.h:15: too few arguments for constructor `B'
strange.h:15: in base initialization for class `D'
math[/u3/xjzhu/postnews][32] exit
math[/u3/xjzhu/postnews][33]
script done on Sun Dec  6 16:27:39 1992
/***********************************************************/