In Section 3.2, TARPL says that "standard allocators (including jemalloc, the one used by default in Rust) generally consider passing in 0 for the size of an allocation as Undefined Behaviour."
However, the C standard and jemalloc manual says allocating zero bytes
should succeed:
- C11 7.22.3 paragraph 1: "If the size of the space requested is zero, the behavior is implementation-defined: either a null pointer is returned, or the behavior is as if the size were some nonzero value, except that the returned pointer shall not be used to access an object."
- [jemalloc manual](http://www.freebsd.org/cgi/man.cgi?query=jemalloc&sektion=3): "The malloc and calloc functions return a pointer to the allocated memory if successful; otherwise a NULL pointer is returned and errno is set to ENOMEM."
+ Note that the description for `allocm` says "Behavior is undefined if size is 0," but it is an experimental API.
This permits collections with `String` keys to be ranged over with
`&str` bounds. The `K` defaults for `Min` and `Max` permit the default
type parameter fallback to work with things like
```rust
use std::collections::{BTreeSet, Bound};
let set = BTreeSet::<String>::new();
set.range(Bound::Included("a"), Bound::Unbounded);
```
Without the defaults, the type of the maximum bound would be
unconstrained.
r? @Gankro
This permits collections with `String` keys to be ranged over with
`&str` bounds. The `K` defaults for `Min` and `Max` permit the default
type parameter fallback to work with things like
```rust
use std::collections::{BTreeSet, Bound};
let set = BTreeSet::<String>::new();
set.range(Bound::Included("a"), Bound::Unbounded);
```
Without the defaults, the type of the maximum bound would be
unconstrained.
'work' can refer to the game itself, ie, 'this compiles but the game isn't finished,'
so 'compile' is a more clear way to describe the problem.
Thanks jhun on irc
'work' can refer to the game itself, ie, 'this compiles but the game isn't finished,'
so 'compile' is a more clear way to describe the problem.
Thanks jhun on irc
This changes the current behaviour for two cases (that I know of)
```rust
mod foo {
extern crate bar;
}
// `bar::` changes to `foo::bar::`
```
```rust
extern crate bar as quux;
// `bar::` changes to `quux::`
```
For example:
```rust
mod foo {
extern crate core;
}
fn assert_clone<T>() where T : Clone { }
fn main() {
assert_clone::<foo::core::atomic::AtomicBool>();
// error: the trait `core::clone::Clone` is not implemented for the type `core::atomic::AtomicBool` [E0277]
// changes to
// error: the trait `foo::core::clone::Clone` is not implemented for the type `foo::core::atomic::AtomicBool` [E0277]
}
```
Notably the following test case broke:
```rust
#[bench]
fn bar(x: isize) { }
//~^ ERROR mismatched types
//~| expected `fn(&mut test::Bencher)`
// changed to
//~| expected `fn(&mut __test::test::Bencher)`
```
If a crate is linked multiple times the path with the least segments is stored.
Partially addresses #1920. (this doesn't solve the issue raised about re-exports)
r? @nikomatsakis
We were burying the reason to use this function below a bunch of caveats about
its usage. That's backwards. Why a function should be used belongs at the top of
the docs, not the bottom.
Also, add some extra links to related functions mentioned in the body.
/cc @abhijeetbhagat who pointed this out on IRC
- Move "Destructuring" after "Multiple patterns", because some of
later sections include examples which make use of destructuring.
- Move "Ignoring bindings" after "Destructoring", because the former
features Result<T,E> destructuring. Some of examples in later
sections use "_" and "..", so "Ignoring bindings" must be
positioned before them.
- Fix#27347 by moving "Ref and mut ref" before "Ranges" and
"Bindings", because "Bindings" section includes a somewhat
difficult example, which also makes use of "ref" and "mut ref"
operators.
I was reading through the docs and came across a section that felt awkward.
I've tried to improve the flow by splitting up and reversing the explanations of
Arc and Mutex with some example code in between.
The "This would have have happened" bit is unfortunate but I couldn't see any
other way to illustrate it. The compiler errors didn't really help tell the
story in this particular instance so it still feels a bit forced. However I do think it's
an a small improvement...
Does anyone have any other ideas that might flow better?
