http://xyst.i2p/DEBUG/cppcheck/57.html
\return Cross-product inline std :: array < real , 3 > cross ( const std :: array < real , 3 >& v1 , const std :: array < real , 3 >& v2 ) { real rx , ry , rz ; cross ( v1 [ 0 ], v1 [ 1 ], v1 [ 2 ], v2 [ 0 ], v2 [ 1 ], v2 [ 2 ], rx , ry , rz ); return { std :: move ( rx ), std :: move ( ry ), std :: move ( rz ) }; } //!