#include <boost/qvm/vec_index.hpp>
namespace boost { namespace qvm { //Only enabled if: // is_vec<A>::value template <class A> typename vec_traits<A>::scalar_type & vec_index_write( A & a, int i ); } }
A mutable reference to the i-th element of a.
i >= 0 && i < vec_traits<A>::dim.
This function uses template metaprogramming and can be used even if the optional access function vec_traits<A>::write_element_idx is not available.