if src.layout.size != dest.layout.size {
// FIXME: This should be an assert instead of an error, but if we transmute within an
// array length computation, `typeck` may not have yet been run and errored out. In fact
if src.layout.size != dest.layout.size {
// FIXME: This should be an assert instead of an error, but if we transmute within an
// array length computation, `typeck` may not have yet been run and errored out. In fact