// Copyright 2012 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. enum box_impl = { mut f: T }; fn set_box_impl(b: box_impl<@const T>, v: @const T) { b.f = v; } fn main() { let b = box_impl::<@int>({mut f: @3}); set_box_impl(b, @mut 5); //~^ ERROR values differ in mutability // No error when type of parameter actually IS @const int let x: @const int = @3; // only way I could find to upcast let b = box_impl::<@const int>({mut f: x}); set_box_impl(b, @mut 5); }