#![feature(box_syntax)] type Noncopyable = Box; struct Foo { copied: isize, moved: Box, noncopyable: Noncopyable } fn test0(f: Foo, g: Noncopyable, h: Noncopyable) { // just copy implicitly copyable fields from `f`, no moves: let _b = Foo {moved: box 1, noncopyable: g, ..f}; let _c = Foo {moved: box 2, noncopyable: h, ..f}; } fn test1(f: Foo, g: Noncopyable, h: Noncopyable) { // copying move-by-default fields from `f`, so move: let _b = Foo {noncopyable: g, ..f}; let _c = Foo {noncopyable: h, ..f}; //~ ERROR use of moved value: `f.moved` } fn main() {}