Forbid type parameters and global paths in macro invocations
Fixes#28558.
This is a [breaking-change]. For example, the following would break:
```rust
macro_rules! m { () => { () } }
fn main() {
m::<T>!(); // Type parameters are no longer allowed in macro invocations
::m!(); // Global paths are no longer allowed in macro invocations
}
```
Any breakage can be fixed by removing the type parameters or the leading `::` (respectively).
r? @eddyb
Give `ast::ExprKind::Paren` no-op expressions the same ids as their children.
Having `ast::ExprKind::Paren` expressions share ids with their children
- reduces the number of unused `NodeId`s in the hir map and
- guarantees that `tcx.map.expect_expr(ast_expr.id)` is the hir corresponding to `ast_expr`.
This fixes the bug from #34327, which was introduced in #33296 when I assumed the above guarantee.
r? @nrc
Previously, any function using a `ToSocketAddrs` input would fail if
passed a hostname that resolves to an address type different from the
ones recognized by Rust.
This also changes the `LookupHost` iterator to only include the known
address types, as a result, it doesn't have to return `Result`s any
more, which are likely misinterpreted as failed name lookups.
rustdoc: Remove Derived Implementations title
As far as I know whether a trait was derived or not does not change the
public API so there is no need to include this information in the docs.
This title currently just adds an extra divide in the list of trait
implementations which I don't think needs to be there.
Try to fix the nightlies
They look to be failing right after the CMake PR landed. I've diagnosed and confirmed the first issue fixed, the second is a bit of a shot in the dark to see if it fixes things.
Add example with leading zeros
I was searching for this format very long. So I added an example to the prominent section.
I was thinking of putting the keyword leading in the corresponding section as well, what do you think?
r? @steveklabnik
[doc] Fix links in Ownership section of the book
- Add a missing link definition for `[i32]`.
- Like `[stack]` link is pointing to `...#the-stack`, append `#the-heap` to `[heap]` link.
Syntax coloring and more compact diagram
Two cosmetic improvements:
- New content was added a few days ago to the **Closures** chapter but it was missing rust's syntax coloring.
- Also, in the **Crates and Modules** chapter, a diagram was improved to be more symmetric and to take less space.