- Remove the `for Sized?` bound on `core::ops::FnOnce`, as it takes `self` by value and can never be implemented by an unsized type.
- Add a missing `Sized?` bound to the blanket `core::ops::FnMut` impl, as both `Fn` and `FnMut` are `for Sized?`.
This change makes the compiler no longer infer whether types (structures
and enumerations) implement the `Copy` trait (and thus are implicitly
copyable). Rather, you must implement `Copy` yourself via `impl Copy for
MyType {}`.
A new warning has been added, `missing_copy_implementations`, to warn
you if a non-generic public type has been added that could have
implemented `Copy` but didn't.
For convenience, you may *temporarily* opt out of this behavior by using
`#![feature(opt_out_copy)]`. Note though that this feature gate will never be
accepted and will be removed by the time that 1.0 is released, so you should
transition your code away from using it.
This breaks code like:
#[deriving(Show)]
struct Point2D {
x: int,
y: int,
}
fn main() {
let mypoint = Point2D {
x: 1,
y: 1,
};
let otherpoint = mypoint;
println!("{}{}", mypoint, otherpoint);
}
Change this code to:
#[deriving(Show)]
struct Point2D {
x: int,
y: int,
}
impl Copy for Point2D {}
fn main() {
let mypoint = Point2D {
x: 1,
y: 1,
};
let otherpoint = mypoint;
println!("{}{}", mypoint, otherpoint);
}
This is the backwards-incompatible part of #13231.
Part of RFC #3.
[breaking-change]
- Remove the `for Sized?` bound on `core::ops::FnOnce`, as it takes
`self` by value and can never be implemented by an unsized type.
- Add a missing `Sized?` bound to the blanket `core::ops::FnMut` impl,
as both `Fn` and `FnMut` are `for Sized?`.
Right now, `DerefMut` is not `for Sized?`, so you can't impl `DerefMut<T> for Foo` where `Foo` is unsized. However, there is no reason that it can't be `for Sized?`, so this pull request fixes the issue.
Closes#19493.
This adds support for lint groups to the compiler. Lint groups are a way of
grouping a number of lints together under one name. For example, this also
defines a default lint for naming conventions, named `bad_style`. Writing
`#[allow(bad_style)]` is equivalent to writing
`#[allow(non_camel_case_types, non_snake_case, non_uppercase_statics)]`. These
lint groups can also be defined as a compiler plugin using the new
`Registry::register_lint_group` method.
This also adds two built-in lint groups, `bad_style` and `unused`. The contents
of these groups can be seen by running `rustc -W help`.
This is done entirely in the libraries for functions up to 16 arguments.
A macro is used so that more arguments can be easily added if we need.
Note that I had to adjust the overloaded call algorithm to not try
calling the overloaded call operator if the callee is a built-in
function type, to prevent loops.
Closes#15448.
At the moment, writing generic functions for integer types that involve shifting is rather verbose. For example, a function at shifts an integer left by 1 currently requires
use std::num::One;
fn f<T: Int>(x : T) -> T {
x << One::one()
}
If the shift amount is not 1, it's even worse:
use std::num::FromPrimitive;
fn f<T: Int + FromPrimitive>(x: T) -> T {
x << FromPrimitive::from_int(2).unwrap()
}
This patch allows the much simpler implementation
fn f<T: Int>(x: T) -> T {
x << 2
}
It accomplishes this by changing the built-in integer types (and the `Int` trait) to implement `Shl<uint, T>` instead of `Shl<T, T>` as it currently is defined. Note that the internal implementations of `shl` already cast the right-hand side to `uint`. `BigInt` also implements `Shl<uint, BigInt>`, so this increases consistency.
All of the above applies similarly to right shifts, i.e., `Shr<uint, T>`.
This will break code that used the old `Index` trait. Change this code
to use the new `Index` traits. For reference, here are their signatures:
pub trait Index<Index,Result> {
fn index<'a>(&'a self, index: &Index) -> &'a Result;
}
pub trait IndexMut<Index,Result> {
fn index_mut<'a>(&'a mut self, index: &Index) -> &'a mut Result;
}
Closes#6515.
[breaking-change]
Libcore's test infrastructure is complicated by the fact that many lang
items are defined in the crate. The current approach (realcore/realstd
imports) is hacky and hard to work with (tests inside of core::cmp
haven't been run for months!).
Moving tests to a separate crate does mean that they can only test the
public API of libcore, but I don't feel that that is too much of an
issue. The only tests that I had to get rid of were some checking the
various numeric formatters, but those are also exercised through normal
format! calls in other tests.
This change starts denying `*T` in the parser. All code using `*T` should ensure
that the FFI call does indeed take `const T*` on the other side before renaming
the type to `*const T`.
Otherwise, all code can rename `*T` to `*const T`.
[breaking-change]
This breaks a fair amount of code. The typical patterns are:
* `for _ in range(0, 10)`: change to `for _ in range(0u, 10)`;
* `println!("{}", 3)`: change to `println!("{}", 3i)`;
* `[1, 2, 3].len()`: change to `[1i, 2, 3].len()`.
RFC #30. Closes#6023.
[breaking-change]
