Add a method to query the capacity of a BufWriter and BufReader
Besides the obvious of retrieving the parameter used to construct the writer, this method allows consumers to control the number of `flush` calls during write operations. For `BufReader` it gives an upper bound on the returned buffer in `fill_buf` which might influence the allocation behaviour of a consumer.
Step stage0 to bootstrap from 1.42
This also includes a commit which fixes the rustfmt downloading logic to redownload when the rustfmt channel changes, and bumps rustfmt to a more recent version.
Previously the debug assertions in the implementation of catch_unwind
used to verify consistency of the panic count by checking that the count
is zero just before leaving the function. This incorrectly assumed that
no panic was in progress when entering `catch_unwind`.
Move numeric consts to associated consts step1
A subset of #67913. Implements the first step of RFC https://github.com/rust-lang/rfcs/pull/2700
This PR adds the new constants as unstable constants and defines the old ones in terms of the new ones. Then fix a tiny bit of code that started having naming collisions because of the new assoc consts.
Removed a test that did not seem relevant any longer. Since doing just `u8::MIN` should now indeed be valid.
Document that write_all will not call write if given an empty buffer
Some types of Write instances have a semantic meaning associated with
writing an empty buffer, such as sending an empty packet. This works
when calling `write` directly, and supplying an empty buffer. However,
calling `write_all` on an empty buffer will simply never call `write`,
because `write_all` assumes it has no work to do.
Document this behavior, to help prospective users of
datagram-packet-style Write instances.
Some types of Write instances have a semantic meaning associated with
writing an empty buffer, such as sending an empty packet. This works
when calling `write` directly, and supplying an empty buffer. However,
calling `write_all` on an empty buffer will simply never call `write`,
because `write_all` assumes it has no work to do.
Document this behavior, to help prospective users of
datagram-packet-style Write instances.
Since the docs for the WASI API are now evolving in [WebAssembly/WASI] repo,
I thought it might be useful to update the links in the docs to point to that location
instead of using the outdated `CraneStation/wasmtime` destination.
[WebAssembly/WASI]: https://github.com/WebAssembly/WASI
Rename `Alloc` to `AllocRef`
The allocator-wg has decided to merge this change upstream in https://github.com/rust-lang/wg-allocators/issues/8#issuecomment-577122958.
This renames `Alloc` to `AllocRef` because types that implement `Alloc` are a reference, smart pointer, or ZSTs. It is not possible to have an allocator like `MyAlloc([u8; N])`, that owns the memory and also implements `Alloc`, since that would mean, that moving a `Vec<T, MyAlloc>` would need to correct the internal pointer, which is not possible as we don't have move constructors.
For further explanation please see https://github.com/rust-lang/wg-allocators/issues/8#issuecomment-489464843 and the comments after that one.
Additionally it clarifies the semantics of `Clone` on an allocator. In the case of `AllocRef`, it is clear that the cloned handle still points to the same allocator instance, and that you can free data allocated from one handle with another handle.
The initial proposal was to rename `Alloc` to `AllocHandle`, but `Ref` expresses the semantics better than `Handle`. Also, the only appearance of `Handle` in `std` are for windows specific resources, which might be confusing.
Blocked on https://github.com/rust-lang/miri/pull/1160
Options IP_MULTICAST_TTL and IP_MULTICAST_LOOP are 1 byte on BSD
Options IP_MULTICAST_TTL and IP_MULTICAST_LOOP are 1 byte on BSD and Solaris
See ip(4P) man page:
IP_MULTICAST_TTL Time to live for multicast datagrams. This option
takes an unsigned character as an argument. Its
value is the TTL that IP uses on outgoing multi-
cast datagrams. The default is 1.
IP_MULTICAST_LOOP Loopback for multicast datagrams. Normally multi-
cast datagrams are delivered to members on the
sending host (or sending zone). Setting the
unsigned character argument to 0 causes the oppo-
site behavior, meaning that when multiple zones
are present, the datagrams are delivered to all
zones except the sending zone.
https://docs.oracle.com/cd/E88353_01/html/E37851/ip-4p.htmlhttps://man.openbsd.org/ip.4
Stabilize ManuallyDrop::take
Tracking issue: closes#55422
FCP merge: https://github.com/rust-lang/rust/issues/55422#issuecomment-572653619
Reclaims the doc improvements from closed#62198.
-----
Stable version is a simple change if necessary.
Proposal: [relnotes] (this changes how to best take advantage of `ManuallyDrop`, esp. wrt. `Drop::drop` and finalize-by-value members)
See ip(4P) man page:
IP_MULTICAST_TTL Time to live for multicast datagrams. This option
takes an unsigned character as an argument. Its
value is the TTL that IP uses on outgoing multi-
cast datagrams. The default is 1.
IP_MULTICAST_LOOP Loopback for multicast datagrams. Normally multi-
cast datagrams are delivered to members on the
sending host (or sending zone). Setting the
unsigned character argument to 0 causes the oppo-
site behavior, meaning that when multiple zones
are present, the datagrams are delivered to all
zones except the sending zone.
https://docs.oracle.com/cd/E88353_01/html/E37851/ip-4p.htmlhttps://man.openbsd.org/ip.4
Don't use f64 shims for f32 cmath functions on non 32-bit x86 MSVC
These shims are only needed on 32-bit x86. Additionally since https://reviews.llvm.org/rL268875 LLVM handles adding the shims itself for the intrinsics.
Use 3.6 instead of 3.5 in float fract() documentation
It is not self-explanatory whether the fract() function inverts the fractional part of negative numbers. This change clarifies this possible question (so that it is `.6` not `.4`)
Clean up some diagnostics by making them more consistent
In general:
- Diagnostic should start with a lowercase letter.
- Diagnostics should not end with a full stop.
- Ellipses contain three dots.
- Backticks should encode Rust code.
I also reworded a couple of messages to make them read more clearly.
It might be sensible to create a style guide for diagnostics, so these informal conventions are written down somewhere, after which we could audit the existing diagnostics.
r? @Centril
