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 breaks code that referred to variant names in the same namespace as
their enum. Reexport the variants in the old location or alter code to
refer to the new locations:
```
pub enum Foo {
A,
B
}
fn main() {
let a = A;
}
```
=>
```
pub use self::Foo::{A, B};
pub enum Foo {
A,
B
}
fn main() {
let a = A;
}
```
or
```
pub enum Foo {
A,
B
}
fn main() {
let a = Foo::A;
}
```
[breaking-change]
This implements a considerable portion of rust-lang/rfcs#369 (tracked in #18640). Some interpretations had to be made in order to get this to work. The breaking changes are listed below:
[breaking-change]
- `core::num::{Num, Unsigned, Primitive}` have been deprecated and their re-exports removed from the `{std, core}::prelude`.
- `core::num::{Zero, One, Bounded}` have been deprecated. Use the static methods on `core::num::{Float, Int}` instead. There is no equivalent to `Zero::is_zero`. Use `(==)` with `{Float, Int}::zero` instead.
- `Signed::abs_sub` has been moved to `std::num::FloatMath`, and is no longer implemented for signed integers.
- `core::num::Signed` has been removed, and its methods have been moved to `core::num::Float` and a new trait, `core::num::SignedInt`. The methods now take the `self` parameter by value.
- `core::num::{Saturating, CheckedAdd, CheckedSub, CheckedMul, CheckedDiv}` have been removed, and their methods moved to `core::num::Int`. Their parameters are now taken by value. This means that
- `std::time::Duration` no longer implements `core::num::{Zero, CheckedAdd, CheckedSub}` instead defining the required methods non-polymorphically.
- `core::num::{zero, one, abs, signum}` have been deprecated. Use their respective methods instead.
- The `core::num::{next_power_of_two, is_power_of_two, checked_next_power_of_two}` functions have been deprecated in favor of methods defined a new trait, `core::num::UnsignedInt`
- `core::iter::{AdditiveIterator, MultiplicativeIterator}` are now only implemented for the built-in numeric types.
- `core::iter::{range, range_inclusive, range_step, range_step_inclusive}` now require `core::num::Int` to be implemented for the type they a re parametrized over.
This commit deprecates the entire libtime library in favor of the
externally-provided libtime in the rust-lang organization. Users of the
`libtime` crate as-is today should add this to their Cargo manifests:
[dependencies.time]
git = "https://github.com/rust-lang/time"
To implement this transition, a new function `Duration::span` was added to the
`std::time::Duration` time. This function takes a closure and then returns the
duration of time it took that closure to execute. This interface will likely
improve with `FnOnce` unboxed closures as moving in and out will be a little
easier.
Due to the deprecation of the in-tree crate, this is a:
[breaking-change]
cc #18855, some of the conversions in the `src/test/bench` area may have been a
little nicer with that implemented
The internals of strftime were converted to use a single formatter,
instead of creating and concatenating a bunch of small strings. This
showed ~3x improvement in the benches.
Also, since the formatted time may be going straight to a Writer, TmFmt
was introduced, and is returned from all formatting methods on Tm. This
allows the saving of another string allocation. Anyone wanting a String
can just call .to_string() on the returned value.
[breaking-change]
https://github.com/rust-lang/rfcs/pull/221
The current terminology of "task failure" often causes problems when
writing or speaking about code. You often want to talk about the
possibility of an operation that returns a Result "failing", but cannot
because of the ambiguity with task failure. Instead, you have to speak
of "the failing case" or "when the operation does not succeed" or other
circumlocutions.
Likewise, we use a "Failure" header in rustdoc to describe when
operations may fail the task, but it would often be helpful to separate
out a section describing the "Err-producing" case.
We have been steadily moving away from task failure and toward Result as
an error-handling mechanism, so we should optimize our terminology
accordingly: Result-producing functions should be easy to describe.
To update your code, rename any call to `fail!` to `panic!` instead.
Assuming you have not created your own macro named `panic!`, this
will work on UNIX based systems:
grep -lZR 'fail!' . | xargs -0 -l sed -i -e 's/fail!/panic!/g'
You can of course also do this by hand.
[breaking-change]
`strftime` currently returns a `String`. This does not indicate that
this function may return an error due to to a malformed format string.
This change introduces a `ParseError` enum which indicates the type of
error that occurred. The return type of `strptime` was also changed to
use this new enum instead of returning `Result<String, String>`. Now,
all instances where `strftime` was used need to have their return value
checked to see if it were valid or not.
[breaking-change]
In C, `ctime(t)` is equivalent to `asctime(localtime(t))`, so the result should depend on the local timezone. Current `ctime` is compatible with `asctime` in C, not `ctime`.
This commit renames `ctime` to `asctime` and adds `ctime` which converts the time to the local timezone before formatting it.
This commit also fixes the documentation of them. Current documentation of `ctime` says it returns "a string of the current time." However, it actually returns a string of the time represented as `self`, not the time when it is called.
- When the timezone is UTC, the "zone" field of the RFC 822 format is
"GMT" (or "UT"), not "UTC."
- Although the name of `rfc3999` refers to RFC 3999, the documentation
of it refers only to ISO 8601. This commit adds a description of the
relation between ISO 8601 and RFC 3999.
Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>
In C, `ctime(t)` is equivalent to `asctime(localtime(t))`, so the result
should depend on the local timezone. Current `ctime` is compatible with
`asctime` in C, not `ctime`.
This commit renames `ctime` to `asctime` and adds `ctime` which converts
the time to the local timezone before formatting it.
This commit also fixes the documentation of them. Current documentation
of `ctime` says it returns "a string of the current time." However, it
actually returns a string of the time represented as `self`, not the
time when it is called.
Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>
Being able to index into the bytes of a string encourages
poor UTF-8 hygiene. To get a view of `&[u8]` from either
a `String` or `&str` slice, use the `as_bytes()` method.
Closes#12710.
[breaking-change]
