/* * call-seq: * dvector.where_eq(number) -> int or nil * dvector.where_first_eq(number) -> int or nil * * Returns the index of the first entry in _dvector_ with value equal to _number_, <code>nil</code> if * _dvector_ has no such entry. * * a = Dvector[ 1, 2, -3, 4, -5, 4, 3, -5, 2 ] * a.where_eq(4) -> 3 * a.where_eq(6) -> nil * Dvector[].where_eq(4) -> nil */ VALUE dvector_where_first_eq(VALUE ary, VALUE item) {