270f0eef73
This is the kind of change that one is expected to need to make to accommodate overloaded-`box`. ---- Note that this is not *all* of the changes necessary to accommodate Issue 22181. It is merely the subset of those cases where there was already a let-binding in place that made it easy to add the necesasry type ascription. (For unnamed intermediate `Box` values, one must go down a different route; `Box::new` is the option that maximizes portability, but has potential inefficiency depending on whether the call is inlined.) ---- There is one place worth note, `run-pass/coerce-match.rs`, where I used an ugly form of `Box<_>` type ascription where I would have preferred to use `Box::new` to accommodate overloaded-`box`. I deliberately did not use `Box::new` here, because that is already done in coerce-match-calls.rs. ---- Precursor for overloaded-`box` and placement-`in`; see Issue 22181.
82 lines
1.7 KiB
Rust
82 lines
1.7 KiB
Rust
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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// Tests that two closures cannot simultaneously have mutable
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// and immutable access to the variable. Issue #6801.
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#![feature(box_syntax)]
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fn get(x: &isize) -> isize {
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*x
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}
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fn set(x: &mut isize) {
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*x = 4;
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}
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fn a() {
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let mut x = 3;
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let c1 = || x = 4;
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let c2 = || x * 5; //~ ERROR cannot borrow `x`
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}
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fn b() {
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let mut x = 3;
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let c1 = || set(&mut x);
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let c2 = || get(&x); //~ ERROR cannot borrow `x`
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}
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fn c() {
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let mut x = 3;
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let c1 = || set(&mut x);
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let c2 = || x * 5; //~ ERROR cannot borrow `x`
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}
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fn d() {
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let mut x = 3;
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let c2 = || x * 5;
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x = 5; //~ ERROR cannot assign
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}
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fn e() {
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let mut x = 3;
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let c1 = || get(&x);
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x = 5; //~ ERROR cannot assign
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}
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fn f() {
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let mut x: Box<_> = box 3;
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let c1 = || get(&*x);
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*x = 5; //~ ERROR cannot assign
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}
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fn g() {
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struct Foo {
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f: Box<isize>
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}
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let mut x: Box<_> = box Foo { f: box 3 };
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let c1 = || get(&*x.f);
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*x.f = 5; //~ ERROR cannot assign to `*x.f`
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}
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fn h() {
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struct Foo {
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f: Box<isize>
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}
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let mut x: Box<_> = box Foo { f: box 3 };
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let c1 = || get(&*x.f);
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let c2 = || *x.f = 5; //~ ERROR cannot borrow `x` as mutable
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}
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fn main() {
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}
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