README_DEVELOPERS

To Developers:

Whenever you introduce a new instantiation of the existing types, such as
SpParMat< NEWINDEXTYPE, NEWVALUETYPE, NEWLOCALMATRIX>, you should create 
three traits:

1) Inside promote.h, tell the compiler how to determine the return type of
binop(bool,NEWVALUETYPE) where binop is usually a user defined multiplication.

2) You should do a similar promotion for your NEWLOCALMATRIX, as done at the
end of SpDCCols.h because the compiler can not deduce your NEWLOCALMATRIX's promotion
from the promotion information of its template parameters. At this point, you
should declare promotions for each possible instantiation of your NEWLOCALMATRIX
object. Here is an example:

template <> struct 
promote_trait< NEWLOCALMATRIX<int64_t,double> , NEWLOCALMATRIX<int64_t,bool> >
{
      typedef NEWLOCALMATRIX<int64_t,double> T_promote;
};

3) You should add a mechanism for the compiler to infer the types of template
parameters in your NEWLOCALMATRIX. This allows the compiler to instantiate a
concrete NEWLOCALMATRIX<> object with the promoted type parameters.

template <class NIT, class NNT>  struct 
create_trait< NEWLOCALMATRIX<int64_t, bool> , NIT, NNT >
{
    typedef NEWLOCALMATRIX<NIT,NNT> T_inferred;
    typedef SpTuples<NIT,NNT> TUP_inferred; // required for internals
};
 
For all three, you can use the existing traits as examples.

To Users:

Please avoid declaring vectors (FullyDistVec, FullyDistSpVec, etc) with NT=bool.
Parallel vectors uses vector<NT> internally, which breaks with bool. You are
more than welcome (and encouraged) to declare matrices (SpParMat) with NT=bool.