Now that we've done `fail` -> `panic`, I feel bringing back the error handling guide is a good idea. We had one long ago, but it was removed when conditions were removed.
This doesn't cover the new FromError stuff, but I feel like it's already useful in this state, so I'm sending this PR now.
This fixes#17388.
Note that we don't check type parameters in trait-references and so on, so we accept some nonsense (I opened https://github.com/rust-lang/rust/issues/18865). (It may be easier to just add support for `T::Foo` and deprecate the qpath code until we can implement it more robustly using the trait lookup infrastructure, not sure.)
Pass the unadjusted type into the unsize_info function, which seems to be what it expects. Fixes#17322.
r? @nick29581
Full disclosure: still running make check locally ;)
This adds an optional suffix at the end of a literal token:
`"foo"bar`. An actual use of a suffix in a expression (or other literal
that the compiler reads) is rejected in the parser.
This doesn't switch the handling of numbers to this system, and doesn't
outlaw illegal suffixes for them yet.
After more than a month of sitting on this patch, rebasing and tracking down some nasty bugs (there's might be still one out there, but it only manifested in `middle::trans::reflect` which is now gone), I'd like to merge it as it is.
This changeset makes middle::ty safe, linking the lifetime of a type to the type context it was created in.
It's a prerequisite for introducing function-local type contexts to localize types with inference variables, in order to (potentially) free hundreds of MBs from rustc's memory usage peak.
This commit applies the stabilization of std::fmt as outlined in [RFC 380][rfc].
There are a number of breaking changes as a part of this commit which will need
to be handled to migrated old code:
* A number of formatting traits have been removed: String, Bool, Char, Unsigned,
Signed, and Float. It is recommended to instead use Show wherever possible or
to use adaptor structs to implement other methods of formatting.
* The format specifier for Boolean has changed from `t` to `b`.
* The enum `FormatError` has been renamed to `Error` as well as becoming a unit
struct instead of an enum. The `WriteError` variant no longer exists.
* The `format_args_method!` macro has been removed with no replacement. Alter
code to use the `format_args!` macro instead.
* The public fields of a `Formatter` have become read-only with no replacement.
Use a new formatting string to alter the formatting flags in combination with
the `write!` macro. The fields can be accessed through accessor methods on the
`Formatter` structure.
Other than these breaking changes, the contents of std::fmt should now also all
contain stability markers. Most of them are still #[unstable] or #[experimental]
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0380-stabilize-std-fmt.md
[breaking-change]
Closes#18904
This commit adds stability markers for the APIs that have recently been
aligned with [numerics
reform](https://github.com/rust-lang/rfcs/pull/369). For APIs that were
changed as part of that reform, `#[unstable]` is used to reflect the
recency, but the APIs will become `#[stable]` in a follow-up pass.
In addition, a few aspects of the APIs not explicitly covered by the RFC
are marked here -- in particular, constants for floats.
This commit does not mark the `uint` or `int` modules as `#[stable]`,
given the ongoing debate out the names and roles of these types.
Due to some deprecation (see the RFC for details), this is a:
[breaking-change]
Make old-fashioned functions in the `std::os` module utilize `IoResult`.
I'm still investigating the possibility to include more functions in this pull request. Currently, it covers `getcwd()`, `make_absolute()`, and `change_dir()`. The issues covered by this PR are #16946 and #16315.
A few concerns:
- Should we provide `OsError` in distinction from `IoError`? I'm saying this because in Python, those two are distinguished. One advantage that we keep using `IoError` is that we can make the error cascade down other functions whose return type also includes `IoError`. An example of such functions is `std::io::TempDir::new_in()`, which uses `os::make_absolute()` as well as returns `IoResult<TempDir>`.
- `os::getcwd()` uses an internal buffer whose size is 2048 bytes, which is passed to `getcwd(3)`. There is no upper limitation of file paths in the POSIX standard, but typically it is set to 4096 bytes such as in Linux. Should we increase the buffer size? One thing that makes me nervous is that the size of 2048 bytes already seems a bit excessive, thinking that in normal cases, there would be no filenames that even exceeds 512 bytes.
Fixes#16946.
Fixes#16315.
Any ideas are welcomed. Thanks!
