In the process, `Splits` got changed to be more like `CharSplits` in `str` to present the DEI interface.
Note that `treemap` still has a `rev_iter` function because it seems like it would be a significant interface change to expose a DEI - the iterator would have to gain an extra pointer, the completion checks would be more complicated, and it isn't easy to check that such an implementation is correct due to the use of unsafety to subvert the aliasing properties of `&mut`.
This fixes#9391.
This commit deprecates rev_iter, mut_rev_iter, move_rev_iter everywhere (except treemap) and also
deprecates related functions like rsplit, rev_components, and rev_str_components. In every case,
these functions can be replaced with the non-reversed form followed by a call to .rev(). To make this
more concrete, a translation table for all functional changes necessary follows:
* container.rev_iter() -> container.iter().rev()
* container.mut_rev_iter() -> container.mut_iter().rev()
* container.move_rev_iter() -> container.move_iter().rev()
* sliceorstr.rsplit(sep) -> sliceorstr.split(sep).rev()
* path.rev_components() -> path.components().rev()
* path.rev_str_components() -> path.str_components().rev()
In terms of the type system, this change also deprecates any specialized reversed iterator types (except
in treemap), opting instead to use Rev directly if any type annotations are needed. However, since
methods directly returning reversed iterators are now discouraged, the need for such annotations should
be small. However, in those cases, the general pattern for conversion is to take whatever follows Rev in
the original reversed name and surround it with Rev<>:
* RevComponents<'a> -> Rev<Components<'a>>
* RevStrComponents<'a> -> Rev<StrComponents<'a>>
* RevItems<'a, T> -> Rev<Items<'a, T>>
* etc.
The reasoning behind this change is that it makes the standard API much simpler without reducing readability,
performance, or power. The presence of functions such as rev_iter adds more boilerplate code to libraries
(all of which simply call .iter().rev()), clutters up the documentation, and only helps code by saving two
characters. Additionally, the numerous type synonyms that were used to make the type signatures look nice
like RevItems add even more boilerplate and clutter up the docs even more. With this change, all that cruft
goes away.
[breaking-change]
Similar to my recent changes to ~[T]/&[T], these changes remove the vstore abstraction and represent str types as ~(str) and &(str). The Option<uint> in ty_str is the length of the string, None if the string is dynamically sized.
It reflected the obsolete syntax `use a, b, c;` and did not make past the parser (though it was a non-fatal error so we can continue). This legacy affected many portions of rustc and rustdoc as well, so this PR cleans them up altogether.
As a side effect of cleanup, we now have `SCHEMA_VERSION` in `rustdoc::clean` (instead of the crate root), so it has a better chance to be updated when `rustdoc::clean` gets updated.
it reflected the obsolete syntax `use a, b, c;` and did not make
past the parser (though it was a non-fatal error so we can continue).
this legacy affected many portions of rustc and rustdoc as well,
so this commit cleans them up altogether.
This addresses the ICE from #13763, but it does not allow the test to compile,
due to #13768. An alternate test was checked in in the meantime.
Closes#13763
moves computation. ExprUseVisitor is a visitor that walks the AST for a
function and calls a delegate to inform it where borrows, copies, and moves
occur.
In this patch, I rewrite the gather_loans visitor to use ExprUseVisitor, but in
future patches, I think we could rewrite regionck, check_loans, and possibly
other passes to use it as well. This would refactor the repeated code between
those places that tries to determine where copies/moves/etc occur.
Specifically, the method parameter cardinality mismatch or missing
method error message span now gets method itself exactly. It was the
whole expression.
Closes#9390Closes#13684Closes#13709
This patch removes the special auto-rooting for `@` from the borrow checker. With `@` moving into a library, it doesn't make sense to keep this code around anymore. It also simplifies `trans` by removing root checking from there
@nikomatsakis
Closes: #11586
Specifically, the method parameter cardinality mismatch or missing
method error message span now gets method itself exactly. It was the
whole expression.
Closes#9390Closes#13684Closes#13709
This alters the borrow checker's requirements on invoking closures from
requiring an immutable borrow to requiring a unique immutable borrow. This means
that it is illegal to invoke a closure through a `&` pointer because there is no
guarantee that is not aliased. This does not mean that a closure is required to
be in a mutable location, but rather a location which can be proven to be
unique (often through a mutable pointer).
For example, the following code is unsound and is no longer allowed:
type Fn<'a> = ||:'a;
fn call(f: |Fn|) {
f(|| {
f(|| {})
});
}
fn main() {
call(|a| {
a();
});
}
There is no replacement for this pattern. For all closures which are stored in
structures, it was previously allowed to invoke the closure through `&self` but
it now requires invocation through `&mut self`.
The standard library has a good number of violations of this new rule, but the
fixes will be separated into multiple breaking change commits.
Closes#12224
This alters the borrow checker's requirements on invoking closures from
requiring an immutable borrow to requiring a unique immutable borrow. This means
that it is illegal to invoke a closure through a `&` pointer because there is no
guarantee that is not aliased. This does not mean that a closure is required to
be in a mutable location, but rather a location which can be proven to be
unique (often through a mutable pointer).
For example, the following code is unsound and is no longer allowed:
type Fn<'a> = ||:'a;
fn call(f: |Fn|) {
f(|| {
f(|| {})
});
}
fn main() {
call(|a| {
a();
});
}
There is no replacement for this pattern. For all closures which are stored in
structures, it was previously allowed to invoke the closure through `&self` but
it now requires invocation through `&mut self`.
The standard library has a good number of violations of this new rule, but the
fixes will be separated into multiple breaking change commits.
Closes#12224
[breaking-change]
`@` pointers used to have special rooting and regions management. With `@`
moving to standalone library, we don't need to keep that special
treatment around. This patch modifies the way `@` pointers are treated by
treating them as if they were `~` pointers
Region checker and borrow checker were modified in this patch.
Closes#11586
[breaking-change]
This exposes volatile versions of the memset/memmove/memcpy intrinsics.
The volatile parameter must be constant, so this can't simply be a
parameter to our intrinsics.
Now with proper checking of enums and allows unsized fields as the last field in a struct or variant. This PR only checks passing of unsized types and distinguishing them from sized ones. To be safe we also need to control storage.
Closes issues #12969 and #13121, supersedes #13375 (all the discussion there is valid here too).
This currently requires linking against a library like libquadmath (or
libgcc), because compiler-rt barely has any support for this and most
hardware does not yet have 128-bit precision floating point. For this
reason, it's currently hidden behind a feature gate.
When compiler-rt is updated to trunk, some tests can be added for
constant evaluation since there will be support for the comparison
operators.
Closes#13381
This exposes volatile versions of the memset/memmove/memcpy intrinsics.
The volatile parameter must be constant, so this can't simply be a
parameter to our intrinsics.
