// Copyright 2013 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. #![feature(box_syntax)] use std::cell::RefCell; use std::rc::Rc; trait Foo { fn set(&mut self, v: Rc>); } struct B { v: Option>> } impl Foo for B { fn set(&mut self, v: Rc>) { self.v = Some(v); } } struct A { v: Box, } fn main() { let a = A {v: box B{v: None} as Box}; //~^ ERROR `std::rc::Rc>: std::marker::Send` is not satisfied }