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QVM: Quaternions, Vectors, Matrices


#include <boost/qvm/deduce_mat.hpp>

namespace boost
    namespace qvm
        template <
            class M,
            int Rows=mat_traits<Matrix>::rows,
            int Cols=mat_traits<Matrix>::cols>
        struct deduce_mat
            typedef /*unspecified*/ type;


is_mat<M>::value is true.


  • is_mat<deduce_mat<M>::type>::value must be true
  • deduce_mat<M>::type must be copyable
  • mat_traits<deduce_mat<M>::type>::rows==Rows
  • mat_traits<deduce_mat<M>::type>::cols==Cols

This template is used by Boost QVM whenever it needs to deduce a copyable matrix type of certain dimensions from a single user-supplied function parameter of matrix type. The returned type must have accessible copy constructor. Note that M itself may be non-copyable.

The main template definition returns an unspecified copyable matrix type of size Rows x Cols, except if mat_traits<M>::rows==Rows && mat_traits<M>::cols==Cols, in which case it returns M, which is suitable only if M is a copyable type. Boost QVM also defines (partial) specializations for the non-copyable matrix types it produces. Users can define other (partial) specializations for their own types.

A typical use of the deduce_mat template is for specifying the preferred matrix type to be returned by the generic function template overloads in Boost QVM depending on the type of their arguments.