8a461d940c
suggest adding a where-clause when there is an unmet trait-bound that can be satisfied if some type can implement it.
82 lines
2.5 KiB
Rust
82 lines
2.5 KiB
Rust
// 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 <LICENSE-APACHE or
|
|
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
|
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
|
// option. This file may not be copied, modified, or distributed
|
|
// except according to those terms.
|
|
|
|
// Test which of the builtin types are considered POD.
|
|
|
|
use std::rc::Rc;
|
|
|
|
fn assert_copy<T:Copy>() { }
|
|
|
|
trait Dummy { }
|
|
|
|
#[derive(Copy, Clone)]
|
|
struct MyStruct {
|
|
x: isize,
|
|
y: isize,
|
|
}
|
|
|
|
struct MyNoncopyStruct {
|
|
x: Box<char>,
|
|
}
|
|
|
|
fn test<'a,T,U:Copy>(_: &'a isize) {
|
|
// lifetime pointers are ok...
|
|
assert_copy::<&'static isize>();
|
|
assert_copy::<&'a isize>();
|
|
assert_copy::<&'a str>();
|
|
assert_copy::<&'a [isize]>();
|
|
|
|
// ...unless they are mutable
|
|
assert_copy::<&'static mut isize>(); //~ ERROR : std::marker::Copy` is not satisfied
|
|
assert_copy::<&'a mut isize>(); //~ ERROR : std::marker::Copy` is not satisfied
|
|
|
|
// boxes are not ok
|
|
assert_copy::<Box<isize>>(); //~ ERROR : std::marker::Copy` is not satisfied
|
|
assert_copy::<String>(); //~ ERROR : std::marker::Copy` is not satisfied
|
|
assert_copy::<Vec<isize> >(); //~ ERROR : std::marker::Copy` is not satisfied
|
|
assert_copy::<Box<&'a mut isize>>(); //~ ERROR : std::marker::Copy` is not satisfied
|
|
|
|
// borrowed object types are generally ok
|
|
assert_copy::<&'a Dummy>();
|
|
assert_copy::<&'a (Dummy+Copy)>();
|
|
assert_copy::<&'static (Dummy+Copy)>();
|
|
|
|
// owned object types are not ok
|
|
assert_copy::<Box<Dummy>>(); //~ ERROR : std::marker::Copy` is not satisfied
|
|
assert_copy::<Box<Dummy+Copy>>(); //~ ERROR : std::marker::Copy` is not satisfied
|
|
|
|
// mutable object types are not ok
|
|
assert_copy::<&'a mut (Dummy+Copy)>(); //~ ERROR : std::marker::Copy` is not satisfied
|
|
|
|
// unsafe ptrs are ok
|
|
assert_copy::<*const isize>();
|
|
assert_copy::<*const &'a mut isize>();
|
|
|
|
// regular old ints and such are ok
|
|
assert_copy::<isize>();
|
|
assert_copy::<bool>();
|
|
assert_copy::<()>();
|
|
|
|
// tuples are ok
|
|
assert_copy::<(isize,isize)>();
|
|
|
|
// structs of POD are ok
|
|
assert_copy::<MyStruct>();
|
|
|
|
// structs containing non-POD are not ok
|
|
assert_copy::<MyNoncopyStruct>(); //~ ERROR : std::marker::Copy` is not satisfied
|
|
|
|
// ref counted types are not ok
|
|
assert_copy::<Rc<isize>>(); //~ ERROR : std::marker::Copy` is not satisfied
|
|
}
|
|
|
|
pub fn main() {
|
|
}
|