USING: classes kernel layouts math sequences tools.test ; ! erg found this one { fixnum } [ 2 >bignum V{ } [ set-length ] keep length class-of ] unit-test ! overflow bugs [ "hi" most-positive-fixnum 2 * 2 + V{ } clone set-nth ] must-fail [ most-positive-fixnum 2 * 2 + { 1 } clone nth ] must-fail [ most-positive-fixnum 2 * 2 + V{ } clone lengthen ] must-fail [ most-positive-fixnum 2 * 2 + V{ } clone set-length ] must-fail [ 10 V{ } [ set-length ] keep 0.5 swap set-length ] must-fail