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.
46 lines
1.1 KiB
Rust
46 lines
1.1 KiB
Rust
// Copyright 2012 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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// Test that we detect nested calls that could free pointers evaluated
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// for earlier arguments.
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#![feature(box_syntax)]
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fn rewrite(v: &mut Box<usize>) -> usize {
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*v = box 22;
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**v
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}
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fn add(v: &usize, w: Box<usize>) -> usize {
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*v + *w
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}
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fn implicit() {
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let mut a: Box<_> = box 1;
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// Note the danger here:
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//
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// the pointer for the first argument has already been
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// evaluated, but it gets moved when evaluating the second
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// argument!
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add(
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&*a,
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a); //~ ERROR cannot move
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}
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fn explicit() {
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let mut a: Box<_> = box 1;
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add(
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&*a,
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a); //~ ERROR cannot move
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}
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fn main() {}
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