Class lsst::shapelet::MatrixBuilderFactory

template<typename T>
class MatrixBuilderFactory

A factory class for MatrixBuilder, providing more control over workspace memory.

To allocate workspace manually for a MatrixBuilder, we use the following pattern:;

MatrixBuilderFactory<T> factory(...);
MatrixBuilderWorkspace<T> workspace(factory.computeWorkspace());
MatrixBuilder<T> builder = factory(workspace);

Because we aren’t doing anything special with the workspace, however, this is actually exactly equivalent to just constructing the MatrixBuilder directly, i.e.:

MatrixBuilder<T> builder(...);

A more interesting case is if we want to use the same workspace for a pair of MatrixBuilders:

MatrixBuilderFactory<T> factory1(...);
MatrixBuilderFactory<T> factory2(...);
MatrixBuilderWorkspace<T> workspace1(
   std::max(factory1.computeWorkspace(), factory2.computeWorkspace())
);
MatrixBuilderWorkspace<T> workspace2(workspace1);
MatrixBuilder<T> builder1 = factory1(workspace1);
MatrixBuilder<T> builder2 = factory2(workspace2);