Per discussion on the tracking issue, naming `TryFrom`'s associated type
`Error` is generally more consistent with similar traits in the Rust
ecosystem, and what people seem to assume it should be called. It
also helps disambiguate from `Result::Err`, the most common "Err".

See
rust-lang#33417 (comment).

TryFrom<&str> and FromStr are equivalent, so have the latter provide the
former to ensure that. Using TryFrom in the implementation of
`str::parse` means types that implement either trait can use it.
When we're ready to stabilize `TryFrom`, we should update `FromStr` to
suggest implementing `TryFrom<&str>` instead for new code.

See
rust-lang#33417 (comment)
and
rust-lang#33417 (comment).

Refs rust-lang#33417.

This seems to match other uses of "be accessed" in the document.

… to be more precise.

It is more robust to not fail if any directory in a path was created
concurrently. This change lifts rustc internal `create_dir_racy` that
was created to handle such conditions to be new `create_dir_all`
implementation.

It will now correctly fail on existing non-directories.

Ignore the type of error altogether. The rationale is: it doesn't matter
what was the problem if the directory is there. In the previous versions
if the directory was there already we wouldn't even attempt to create
it, so we wouldn't know about the problem neither.

Make test path length smaller in `concurrent_recursive_mkdir` test.

Avoid doing `is_dir` in the fast path.

Add a test for `""` and `"."`.

Unfortunately it was reverted back to a broken state in
e06c515 by accident, so let's bring it forward
again!

Fix race condition in fs::create_dir_all

The code would crash if the directory was created after create_dir_all
checked whether the directory already existed.  This was contrary to
the documentation which claimed to create the directory if it doesn't
exist, implying (but not stating) that there would not be a failure
due to the directory existing.

…uron

Rename TryFrom's associated type and implement str::parse using TryFrom.

Per discussion on the tracking issue, naming `TryFrom`'s associated type `Error` is generally more consistent with similar traits in the Rust ecosystem, and what people seem to assume it should be called. It also helps disambiguate from `Result::Err`, the most common "Err".

See rust-lang#33417 (comment).

`TryFrom<&str>` and `FromStr` are equivalent, so have the latter provide the former to ensure that. Using `TryFrom` in the implementation of `str::parse` means types that implement either trait can use it. When we're ready to stabilize `TryFrom`, we should update `FromStr` to
suggest implementing `TryFrom<&str>` instead for new code.

See rust-lang#33417 (comment)
and rust-lang#33417 (comment).

Refs rust-lang#33417.

Library stabilizations for 1.17

Details of the stabilizations are available in the commits. Includes only library stabilizations; there are a couple of compiler stabilizations that should also be done for 1.17.

Will need a beta backport, which I will create after approval.

r? @alexcrichton

documented order of conversion between u32 an ipv4addr

This fixes rust-lang#40118

…uillaumeGomez

minor wording tweak to slice::{as_ptr, as_mut_ptr}

Per rust-lang#37334, the slice-as-pointer methods mentioned that "modifying the slice may cause its buffer to be reallocated", when in fact modifying the *slice* itself would cause no such change. (It is a borrow, after all!) This is a tweak to the wording of that line to stress it's the *collection* that could cause the buffer to be reallocated.

r? @steveklabnik

Fix typo in mutex.rs docs

This seems to match other uses of "be accessed" in the document.

…sfackler

Fix a spelling error in HashMap documentation, and slightly reword surrounding text for precision

Noticed while reading docs just now.

It's possible that the prior wording *meant* to state that the seed's randomness depends on the exact instant that the system RNG was created, I guess.  But unless there's an API guarantee that this is the case, the wording seems over-precise.  Is there a formal API guarantee that would forbid, say, the system RNG from generating all output using the Intel RDRAND instruction?  I don't think the quality of output in that case would depend on when the RNG was created.  Yet it seems to me like it could well be a valid source of randomness when computing the initial seed.

For that reason, tying the randomness of the seed, to the quality of the RNG's output *at the precise instant the seed is computed*, seems less confining.  That instantaneous quality level could be determined by the quality at the instant the RNG was created -- but instantaneous quality need not be low for that precise reason.

…alexcrichton

Update the cargo submodule again

Unfortunately it was reverted back to a broken state in
e06c515 by accident, so let's bring it forward
again!

Closes rust-lang/cargo#3844