* All I/O now returns IoResult<T> = Result<T, IoError>
* All formatting traits now return fmt::Result = IoResult<()>
* The if_ok!() macro was added to libstd
Unique pointers and vectors currently contain a reference counting
header when containing a managed pointer.
This `{ ref_count, type_desc, prev, next }` header is not necessary and
not a sensible foundation for tracing. It adds needless complexity to
library code and is responsible for breakage in places where the branch
has been left out.
The `borrow_offset` field can now be removed from `TyDesc` along with
the associated handling in the compiler.
Closes#9510Closes#11533
Not only can discriminants be smaller than int now, but they can be
larger than int on 32-bit targets. This has obvious implications for the
reflection interface. Without this change, things fail with LLVM
assertions when we try to "extend" i64 to i32.
It is simply defined as `f64` across every platform right now.
A use case hasn't been presented for a `float` type defined as the
highest precision floating point type implemented in hardware on the
platform. Performance-wise, using the smallest precision correct for the
use case greatly saves on cache space and allows for fitting more
numbers into SSE/AVX registers.
If there was a use case, this could be implemented as simply a type
alias or a struct thanks to `#[cfg(...)]`.
Closes#6592
The mailing list thread, for reference:
https://mail.mozilla.org/pipermail/rust-dev/2013-July/004632.html
This moves the raw struct layout of closures, vectors, boxes, and strings into a
new `unstable::raw` module. This is meant to be a centralized location to find
information for the layout of these values.
As safe method, `repr`, is provided to convert a rust value to its raw
representation. Unsafe methods to convert back are not provided because they are
rarely used and too numerous to write an implementation for each (not much of a
common pattern).
To achieve this, the following changes were made:
* Move TyDesc, TyVisitor and Opaque to std::unstable::intrinsics
* Convert TyDesc, TyVisitor and Opaque to lang items instead of specially
handling the intrinsics module
* Removed TypeDesc, FreeGlue and get_type_desc() from sys
Fixes#3475.
