into variance inference; fix various bugs in variance inference
so that it considers the correct set of constraints; modify infer to
consider the results of variance inference for type arguments.
* Move the type parameter on the `AsciiExt` trait to an associated type named
`Owned`.
* Move `ascii::escape_default` to using an iterator.
This is a breaking change due to the removal of the type parameter on the
`AsciiExt` trait as well as the modifications to the `escape_default` function
to returning an iterator. Manual implementations of `AsciiExt` (or `AsciiExt`
bounds) should be adjusted to remove the type parameter and using the new
`escape_default` should be relatively straightforward.
[breaking-change]
This commit renames the features for the `std::old_io` and `std::old_path`
modules to `old_io` and `old_path` to help facilitate migration to the new APIs.
This is a breaking change as crates which mention the old feature names now need
to be renamed to use the new feature names.
[breaking-change]
Previously an implementation of a stable trait allows implementations of
unstable methods. This updates the stability pass to ensure that all items of an
impl block of a trait are indeed stable on the trait itself.
Pass features along during expansion
Use the set of passed features to detect uses of feature-gated macros without the corresponding feature enabled.
Fix#22234.
----
Also, the framework this add (passing along a reference to the features in the expansion context) is a necessary precursor for landing a properly feature-gated desugaring-based overloaded-`box` and placement-`in` (#22181).
----
This is fixing a bug, but since there might be code out there that is unknowingly taking advantage of that bug, I feel obligated to mark this as a:
[breaking-change]
It's not clear what this means, because a macro in item position can expand to zero or more items. For now we disallow it, which is technically a
[breaking-change]
but is landing without an RFC. The `pub` keyword previously had no effect, which seems quite unintended.
Fixes#18317.
Fixes#14660.
Add `#[rustc_error]` annotation, which causes trans to signal an error
if found on the `main()` function. This lets you write tests that live
in `compile-fail` but are expected to compile successfully. This is
handy when you have many small variations on a theme that you want to
keep together, and you are just testing the type checker, not the
runtime semantics.
r? @pnkfelix
It is only allowed in paths now, where it will either work inside a `trait`
or `impl` item, or not resolve outside of it.
[breaking-change]
Closes#22137
It's not clear what this means, because a macro in item position can expand to
zero or more items. For now we disallow it, which is technically a
[breaking-change]
but is landing without an RFC. The `pub` keyword previously had no effect,
which seems quite unintended.
Fixes#18317.
Fixes#14660.
if found on the `main()` function. This lets you write tests that live
in `compile-fail` but are expected to compile successfully. This is
handy when you have many small variations on a theme that you want to
keep together, and you are just testing the type checker, not the
runtime semantics.
Names of structs, enums, traits, type aliases and type parameters (i.e. all identifiers that can be used as full paths in type position) are not allowed to match the names of primitive types.
See #20427 for more information.
This is a minor [breaking-change]
It is only allowed in paths now, where it will either work inside a `trait`
or `impl` item, or not resolve outside of it.
[breaking-change]
Closes#22137
There are a number of holes that the stability lint did not previously cover,
including:
* Types
* Bounds on type parameters on functions and impls
* Where clauses
* Imports
* Patterns (structs and enums)
These holes have all been fixed by overriding the `visit_path` function on the
AST visitor instead of a few specialized cases. This change also necessitated a
few stability changes:
* The `collections::fmt` module is now stable (it was already supposed to be).
* The `thread_local:👿:Key` type is now stable (it was already supposed to
be).
* The `std::rt::{begin_unwind, begin_unwind_fmt}` functions are now stable.
These are required via the `panic!` macro.
* The `std::old_io::stdio::{println, println_args}` functions are now stable.
These are required by the `print!` and `println!` macros.
* The `ops::{FnOnce, FnMut, Fn}` traits are now `#[stable]`. This is required to
make bounds with these traits stable. Note that manual implementations of
these traits are still gated by default, this stability only allows bounds
such as `F: FnOnce()`.
Closes#8962Closes#16360Closes#20327
This renames the PrivateNoMangleFns lint to allow both to happen in a
single pass, since they do roughly the same work.
Closes#21856
Open questions:
[ ]: Do the tests actually pass (I'm running make check and running out the door now)
[ ]: Is the name of this lint ok. it seems to mostly be fine with [convention](cc53afbe5d/text/0344-conventions-galore.md (lints))
[ ]: I'm not super thrilled about the warning text
r? @kmcallister (Shamelessly nominating because you were looking at my other ticket)
There are a number of holes that the stability lint did not previously cover,
including:
* Types
* Bounds on type parameters on functions and impls
* Where clauses
* Imports
* Patterns (structs and enums)
These holes have all been fixed by overriding the `visit_path` function on the
AST visitor instead of a few specialized cases. This change also necessitated a
few stability changes:
* The `collections::fmt` module is now stable (it was already supposed to be).
* The `thread_local:👿:Key` type is now stable (it was already supposed to
be).
* The `std::rt::{begin_unwind, begin_unwind_fmt}` functions are now stable.
These are required via the `panic!` macro.
* The `std::old_io::stdio::{println, println_args}` functions are now stable.
These are required by the `print!` and `println!` macros.
* The `ops::{FnOnce, FnMut, Fn}` traits are now `#[stable]`. This is required to
make bounds with these traits stable. Note that manual implementations of
these traits are still gated by default, this stability only allows bounds
such as `F: FnOnce()`.
Additionally, the compiler now has special logic to ignore its own generated
`__test` module for the `--test` harness in terms of stability.
Closes#8962Closes#16360Closes#20327
[breaking-change]
This is a resurrection and heavy revision/expansion of a PR that pcwalton did to resolve#8861.
The most relevant, user-visible semantic change is this: #[unsafe_destructor] is gone. Instead, if a type expression for some value has a destructor, then any lifetimes referenced within that type expression must strictly outlive the scope of the value.
See discussion on https://github.com/rust-lang/rfcs/pull/769
Some compile-fail tests illustrated cases to be rejected by dropck,
including ones that check cyclic data cases designed to exposed bugs
if they are actually tricked into running by an unsound analysis.
E.g. these exposed bugs in earlier broken ways of handling `Vec<T>`.
(Note that all the uses of `unsafe_destructor` are just placating the
simple analysis used for that feature, which will eventually go away
once we have put the dropck through its paces.)
