7828c3dd28
https://github.com/rust-lang/rfcs/pull/221 The current terminology of "task failure" often causes problems when writing or speaking about code. You often want to talk about the possibility of an operation that returns a Result "failing", but cannot because of the ambiguity with task failure. Instead, you have to speak of "the failing case" or "when the operation does not succeed" or other circumlocutions. Likewise, we use a "Failure" header in rustdoc to describe when operations may fail the task, but it would often be helpful to separate out a section describing the "Err-producing" case. We have been steadily moving away from task failure and toward Result as an error-handling mechanism, so we should optimize our terminology accordingly: Result-producing functions should be easy to describe. To update your code, rename any call to `fail!` to `panic!` instead. Assuming you have not created your own macro named `panic!`, this will work on UNIX based systems: grep -lZR 'fail!' . | xargs -0 -l sed -i -e 's/fail!/panic!/g' You can of course also do this by hand. [breaking-change]
146 lines
3.7 KiB
Rust
146 lines
3.7 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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// Note: the borrowck analysis is currently flow-insensitive.
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// Therefore, some of these errors are marked as spurious and could be
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// corrected by a simple change to the analysis. The others are
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// either genuine or would require more advanced changes. The latter
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// cases are noted.
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fn borrow(_v: &int) {}
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fn borrow_mut(_v: &mut int) {}
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fn cond() -> bool { panic!() }
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fn produce<T>() -> T { panic!(); }
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fn inc(v: &mut Box<int>) {
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*v = box() (**v + 1);
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}
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fn loop_overarching_alias_mut() {
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// In this instance, the borrow encompasses the entire loop.
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let mut v = box 3;
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let mut x = &mut v;
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**x += 1;
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loop {
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borrow(&*v); //~ ERROR cannot borrow
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}
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}
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fn block_overarching_alias_mut() {
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// In this instance, the borrow encompasses the entire closure call.
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let mut v = box 3;
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let mut x = &mut v;
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for _ in range(0i, 3) {
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borrow(&*v); //~ ERROR cannot borrow
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}
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*x = box 5;
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}
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fn loop_aliased_mut() {
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// In this instance, the borrow is carried through the loop.
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let mut v = box 3;
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let mut w = box 4;
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let mut _x = &w;
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loop {
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borrow_mut(&mut *v); //~ ERROR cannot borrow
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_x = &v;
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}
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}
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fn while_aliased_mut() {
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// In this instance, the borrow is carried through the loop.
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let mut v = box 3;
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let mut w = box 4;
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let mut _x = &w;
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while cond() {
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borrow_mut(&mut *v); //~ ERROR cannot borrow
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_x = &v;
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}
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}
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fn loop_aliased_mut_break() {
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// In this instance, the borrow is carried through the loop.
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let mut v = box 3;
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let mut w = box 4;
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let mut _x = &w;
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loop {
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borrow_mut(&mut *v);
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_x = &v;
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break;
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}
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borrow_mut(&mut *v); //~ ERROR cannot borrow
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}
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fn while_aliased_mut_break() {
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// In this instance, the borrow is carried through the loop.
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let mut v = box 3;
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let mut w = box 4;
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let mut _x = &w;
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while cond() {
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borrow_mut(&mut *v);
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_x = &v;
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break;
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}
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borrow_mut(&mut *v); //~ ERROR cannot borrow
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}
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fn while_aliased_mut_cond(cond: bool, cond2: bool) {
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let mut v = box 3;
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let mut w = box 4;
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let mut x = &mut w;
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while cond {
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**x += 1;
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borrow(&*v); //~ ERROR cannot borrow
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if cond2 {
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x = &mut v; //~ ERROR cannot borrow
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}
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}
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}
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fn loop_break_pops_scopes<'r>(_v: &'r mut [uint], f: |&'r mut uint| -> bool) {
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// Here we check that when you break out of an inner loop, the
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// borrows that go out of scope as you exit the inner loop are
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// removed from the bitset.
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while cond() {
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while cond() {
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// this borrow is limited to the scope of `r`...
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let r: &'r mut uint = produce();
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if !f(&mut *r) {
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break; // ...so it is not live as exit the `while` loop here
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}
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}
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}
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}
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fn loop_loop_pops_scopes<'r>(_v: &'r mut [uint], f: |&'r mut uint| -> bool) {
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// Similar to `loop_break_pops_scopes` but for the `loop` keyword
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while cond() {
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while cond() {
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// this borrow is limited to the scope of `r`...
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let r: &'r mut uint = produce();
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if !f(&mut *r) {
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continue; // ...so it is not live as exit (and re-enter) the `while` loop here
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}
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}
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}
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}
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fn main() {}
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