on 17.08.2009 at 10:30 joel wrote :
No, I was speaking of matrix of user defined nuemrical types ;) But the discussion on shape is good oops, my bad
Yet again, use policy. It'll clutter the code to have 34567 names for different object while having the shape as a template policy is prolly better. ANd the enforcement of shape semantic has to be implicit and static, no need for need_simmetric.
matrix<float, settings(diagonal)> m;
For checking arguments of elements with same shape, just use tag dispatching or SFINAE instead of concrete typing.
my question is: is a common user able to write just what he wants? e.g. i want to take as a parameter in my function a diagonal matrix, shoud i write void foo(const matrix<float, settings(symmetric)> &m); to me it is more convenient to write void foo(const symmetric_matrix<float> &m); //it's even shorter my point is since we need to implement such features why not in a distinct type? that will provide proper interface to each concrete featured entity e.g. a symmetric matrix can have such an interface: template<...> //parameters omitted for simplicity class symmetric_matrix : public symmetric_matrix_expression<...> { //... explicit symmetric_matrix(size_t size); //since it is square //... //there's no need for void resize(size_t size); //distinct rows/columns //etc... //numbers } so a user will not even be able to write such nonsensical code like symmetric1.resize(10, 10); //note unnecessary duplication because symmetric_matix does not even provide such interface and will not leave user wandering if he missed the key and typed '(10, 19)' with unreadable compiler error somewhere in instantiated templates as far as i know policies can not do this unless it is full specialized and the latter i think is equivalent to a distinct type -- Pavel