on 3/23/00 1:13 PM, oon-digest at owner-oon-digest@oonumerics.org wrote:
> void rank1Update(Matrix& A, const Vector& x)
> {
> for (int i=0; i < A.rows(); ++i)
> for (int j=0; j < A.cols(); ++j)
> A(i,j) += x(i) * x(j);
> }
>
> [...] However, the compiler can't be sure that the data in the matrix A
> doesn't overlap the data in the vector x -- there is a possibility that
> writing to A(i,j) could change the value of x(i) partway through.
This one has always bothered me - why isn't "const" enough to tell the
compiler that x isn't being changed by the assignment.
Jim
-- ------------------------------------------------------------------------ James A. Crotinger Los Alamos National Lab email: jac@lanl.gov Technical Staff Member CIC-ACL, MS B287 phone: 505-665-6022 Advanced Computing Lab Los Alamos, NM 87545 fax: 505-665-4939--------------------- Object Oriented Numerics List -------------------------- * To subscribe/unsubscribe: use the handy web form at http://oonumerics.org/oon/ * If this doesn't work, please send a note to owner-oon-list@oonumerics.org
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