identity_operator constructor that takes MatrixType A

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In order to use the identity_operator as a preconditioner in something like this

template<typename PreconditionerType>
void solve() {
  cusp::csr_matrix<int,float,cusp::device_memory> A;
  PreconditionerType M(A);
  cusp::krylov::cg(A, x, b, monitor, M);
}

I found it necessary to add an identity_operator constructor like so

template<typename MatrixType>
identity_operator(const MatrixType& A)
: Parent(A.num_rows, A.num_cols) {}

regards,
Sam

Original issue reported on code.google.com by sam.mos...@gmail.com on 22 Nov 2010 at 12:48