The solution which uses braces to release the borrow
before it is moved is only required to satisfy the 2015
edition borrow checker.
All other examples give the expected results for both
2015 and 2018 editions.
`codegen_allocator` and `write_metadata` mutate the underlying LLVM module. As
such, it makes sense for these two functions to receive a mutable reference to
the module (as opposed to an immutable one).
make generalization code create new variables in correct universe
In our type inference system, when we "generalize" a type T to become
a suitable value for a type variable V, we sometimes wind up creating
new inference variables. So, for example, if we are making V be some
subtype of `&'X u32`, then we might instantiate V with `&'Y u32`.
This generalized type is then related `&'Y u32 <: &'X u32`, resulting
in a region constriant `'Y: 'X`. Previously, however, we were making
these fresh variables like `'Y` in the "current universe", but they
should be created in the universe of V. Moreover, we sometimes cheat
in an invariant context and avoid creating fresh variables if we know
the result must be equal -- we can only do that when the universes
work out.
Fixes#57843
r? @pnkfelix
Before this commit, if the builtin target was found, but an error
happened when instantiating it (e.g. validating the target
specification file failed, etc.), then we ignored those errors
and proceeded to try to find a `target_triple.json` file, and if
that failed, reported that as an error.
With this commit, if rustc is supposed to provide the builtin target,
and something fails while instantiating it, that error will
get properly propagated.
Make overflowing and wrapping negation const
Remember that the signed and unsigned versions are slightly different here, so there's four functions made const instead of just two.
Reduce Some Code Repetitions like `(n << amt) >> amt`
This Pull Request is related to [#49937](https://github.com/rust-lang/rust/issues/49937).
This Pull Request has reduced repetition of `(n << amt) >> amt`.
Fix typo in std::future::Future docs
I am not quite sure if this is actually a typo but
1. to me the sentence doesn't make sense if it says "expect"
2. I hope that `Future`s are not really allowed to cause memory unsafety if they are polled after completion.
Explain a panic in test case net::tcp::tests::double_bind
Those who try to build libstd on the Windows Subsystem for Linux experience a single failing test, where the point of failure is an explicit but anonymous panic, as reported in https://github.com/rust-lang/rust/issues/49367
This commit somewhat explains why and allows diagnosing a little.
