This PR adds rules for negative implementations. It follows pretty much what the [RFC](https://github.com/rust-lang/rfcs/blob/master/text/0019-opt-in-builtin-traits.md) says with 1 main difference:
Instead of positive implementations override negative implementations, this have been implemented in a way that a negative implementation of `Trait` for `T` will overlap with a positive implementation, causing a coherence error.
@nikomatsakis r?
cc #13231
[breaking-change]
Originally, this was going to be discussed and revisted, however I've been working on this for months, and a rebase on top of master was about 1 flight's worth of work so I just went ahead and did it.
This gets you as far as being able to target powerpc with, eg:
LD_LIBRARY_PATH=./x86_64-unknown-linux-gnu/stage2/lib/ x86_64-unknown-linux-gnu/stage2/bin/rustc -C linker=powerpc-linux-gnu-gcc --target powerpc-unknown-linux-gnu hello.rs
Would really love to get this out before 1.0. r? @alexcrichton
It's passed to the underlying reader, so uninitialized memory == sad
times.
We might want to shrink the default buffer size as well. 64k is pretty
huge. Java uses 8k by default, and Go uses 4k for reference.
r? @alexcrichton
Also adjusted some of the FFI definitions because apparently they don't use the long pointer prefix.
Gives a free performance boost because `SRWLock` is several times faster than `CriticalRegion` on every Windows system tested.
Fixes#19962
It's passed to the underlying reader, so uninitialized memory == sad
times.
We might want to shrink the default buffer size as well. 64k is pretty
huge. Java uses 8k by default, and Go uses 4k for reference.
A derived implementation would not be appropriate for the Buffered types
since the buffer is both huge (64k by default) and full of uninitialized
memory. Instead of printing the whole thing, we display how full it is.
I also altered MultiWriter to make it generic over Writers instead of
taking Box<Writer> trait objects. Box<Writer> implements Writer so
existing use cases should continue to work, and this enables a more
useful Show implementation in applicable cases.
The change to MultiWriter may break code that uses it, but any fixes
should be easy.
[breaking-change]
On DragonFly pthread_{mutex,rwlock,condvar}_destroy() returns EINVAL
when called on a pthread_{mutex,rwlock,condvar}_t that was just
initialized via PTHREAD_{MUTEX,RWLOCK,CONDVAR}_INITIALIZER and not used
in the meantime or initialized via pthread_{mutex,rwlock,condvar}_init().
Change the code to treat a return value of EINVAL on DragonFly as success.
This gets rid of the 'experimental' level, removes the non-staged_api
case (i.e. stability levels for out-of-tree crates), and lets the
staged_api attributes use 'unstable' and 'deprecated' lints.
This makes the transition period to the full feature staging design
a bit nicer.
