# QVM: Quaternions, Vectors, Matrices

### mat_traits<Matrix>::cols

    static int const cols = /*user-defined*/;

This member of user-defined (partial) specializations of the mat_traits template must be a compile-time integer constant greater than zero that defines the number of columns of a user-defined matrix type.

See also: assign(mat,mat) | cmp(mat,mat) | convert_to(mat) | convert_to(quat) | deduce_mat | deduce_mat2 | determinant | inverse(mat) | mat_traits | mat_traits_defaults | operator!=(mat,mat) | operator*(mat,mat) | operator*(mat,vec) | operator*(vec,mat) | operator*=(mat,mat) | operator+(mat,mat) | operator+=(mat,mat) | operator-(mat,mat) | operator-=(mat,mat) | operator==(mat,mat) | rotate(mat,vec,scalar) | rotate_x(mat,scalar) | rotate_y(mat,scalar) | rotate_z(mat,scalar) | SFINAE/enable_if | set_identity(mat) | set_rot(mat,vec,scalar) | set_rotx(mat,scalar) | set_roty(mat,scalar) | set_rotz(mat,scalar) | set_zero(mat) | transform_point | transform_vector | translation