Work towards #4846.
- Institute new region defaults where all omitted regions get a fresh lifetime.
- Require explicit region names except in functions.
- Fix a bug in region parameterization inference. I've been putting this off because it will not be important when we remove RP inference in favor of explicit declarations, but then it was blocking this patch.
r? @pcwalton
Two changes:
- The first fixes an inconsistency in coherence whereby extension methods were added to the inherent methods table, but only in cross-crate scenarios. This causes some minor fallout in tests and so forth. In one case (comm) I added inherent and trait methods so as to avoid the need to import traits like `GenericPort` just to use a port.
- The second makes objects not implement the associated trait, as discussed in #5087.
r? @pcwalton
When parsing bytes from a wire, there is a need to parse floating-point bytes to float values ([u8*4] to f32, [u8*8] to f64). This can be done via cast::transmute, but there is no way to do it safely.
It's quite common, so I think I't better to support it in core library.
This patch series changes a handful of vec functions to return references instead of copies. The one downside with making this change is that these functions aren't usable in a couple cases now due to some purity complaints. For example, this [change](c31e81a532 (L1R87)). I couldn't figure out a way to get `last` to work on a `@mut ~[...]` type, so I ended up having to use `*crate_cache[crate_cache.len() - 1].metas`.
7.3x speedup in string map search speed on a microbenchmark of pure hashmap
searching against a constant string, due to the lack of allocations.
I ran into a few snags.
1. The way the coherence check is set up, I can't implement `Equiv<@str>` and
`Equiv<~str>` for `&str` simultaneously.
2. I wanted to implement `Equiv<T>` for all `T:Eq` (i.e. every type can be
compared to itself if it implements `Eq`), but the coherence check didn't
like that either.
3. I couldn't add this to the `Map` trait because `LinearMap` needs special
handling for its `Q` type parameter: it must not only implement `Equiv<T>`
but also `Hash` and `Eq`.
4. `find_equiv(&&"foo")` doesn't parse, because of the double ampersand. It has
to be written `find_equiv(& &"foo")`. We can probably just fix this.
Nevertheless, this is a huge win; it should address a major source of
performance problems, including the one here:
http://maniagnosis.crsr.net/2013/02/creating-letterpress-cheating-program.html
Macro invocations with path separators (e.g. foo::bar!()) now produce a sensible error message, rather than an assertion failure. Also added compile-fail test case.
Fixes#5218 ?
Update region inference for traits so that a method with explicit self doesn't incorrectly cause the entire trait to be tagged as being region-parameterized.
Fixes#5224.
r? @pcwalton
