Squashed at reviewer's request:
Add heading at the end of the introductory material
Spice up introductory paragraphs a bit
Use quotes instead of <code> for phrase
Remove "other" in "other restrictions" (it's not obvious that any other
restrictions have been mentioned)
"Default methods" is a second-level heading, but is not a subsection of
"Where clause"
Reword "Default methods" introduction: it's not the "last feature" on
this page
This includes a new example with Rectangle, instead of reusing HasArea,
because fn area would require the Mul trait, and the added complexity of
that would be better left for the Operators and Overloading chapter.
Squashed at reviewer's request: Move teaser for trait bounds to bottom
This introduces a test for #23389 and improves the error behaviour to treat the malformed LHS as an error, not a compiler bug.
The parse phase that precedes the call to `check_lhs_nt_follows` could possibly be enhanced to police the format itself (which the old code suggests was the original intention), but I'm not sure that's any nicer than just parsing the matcher as generic rust code and then policing the specific requirements for being a macro matcher afterwards (as this does).
Fixes#23389
I'll be adding more commits to this PR as the weekend progresses. Was hoping to make this a mega-PR, but getting some eyes on this early would be nice too.
r? @steveklabnik
r? @eddyb on the object safety bits
cc @michaelsproul
Part of #24407
Hi all.
This is my first contribution to Rust and fixes an issue causing an invalid error message to be presented to the user when using unit struct as length of a repeat expression, issue #27008. The solution is based on suggestions by @oli-obk, but as I'm a complete newbie to this, I have no clue if I got them right :)
The biggest concern I have is that if the `NodeId` I'm returning is the correct one or not (it's not meaningful in this case but I think it would be nice to get it right).
As title!
I should probably be bunching these up a bit more, but I'm not sure when my time is going to disappear on me. Once my schedule stabilises I'll try to start batching them into larger PRs.
Part of #24407.
r? @Manishearth
Was browsing somebody else's code and came across a snippet using labels. Looking around, it seems like there was an example for this in [rustbyexample](http://rustbyexample.com/flow_control/loop/nested.html) but none in trpl.
Refactors the "desugaring" of closures to expose the types of the upvars. This is necessary to be faithful with how actual structs work. The reasoning of the particular desugaring that I chose is explained in a fairly detailed comment.
As a side-effect, recursive closure types are prohibited unless a trait object intermediary is used. This fixes#25954 and also eliminates concerns about unrepresentable closure types that have infinite size, I believe. I don't believe this can cause regressions because of #25954.
(As for motivation, besides #25954 etc, this work is also intended as refactoring in support of incremental compilation, since closures are one of the thornier cases encountered when attempting to split node-ids into item-ids and within-item-ids. The goal is to eliminate the "internal def-id" distinction in astdecoding. However, I have to do more work on trans to really make progress there.)
r? @nrc
Macro desugaring of `in PLACE { BLOCK }` into "simpler" expressions following the in-development "Placer" protocol.
Includes Placer API that one can override to integrate support for `in` into one's own type. (See [RFC 809].)
[RFC 809]: https://github.com/rust-lang/rfcs/blob/master/text/0809-box-and-in-for-stdlib.md
Part of #22181
Replaced PR #26180.
Turns on the `in PLACE { BLOCK }` syntax, while leaving in support for the old `box (PLACE) EXPR` syntax (since we need to support that at least until we have a snapshot with support for `in PLACE { BLOCK }`.
(Note that we are not 100% committed to the `in PLACE { BLOCK }` syntax. In particular I still want to play around with some other alternatives. Still, I want to get the fundamental framework for the protocol landed so we can play with implementing it for non `Box` types.)
----
Also, this PR leaves out support for desugaring-based `box EXPR`. We will hopefully land that in the future, but for the short term there are type-inference issues injected by that change that we want to resolve separately.
is being used now before the final regionck stage and in some cases SOME
amount of unresolved inference is OK. In fact, we could probably just
allow inference variables as well with only minimal pain.
TyClosure variant; thread this through wherever closure substitutions
are expected, which leads to a net simplification. Simplify trans
treatment of closures in particular.
Currently, `rustc` generates nondeterministic archives, which contain system timestamps. These don't really serve any useful purpose, and enabling deterministic archives moves us a little closer to completely deterministic builds. For a small toy library using `std::ops::{Deref,DerefMut}`, this change actually results in a bit-for-bit identical build every time.
Currently you can hit a link error on MSVC by only referencing static items from
a crate (no functions for example) and then link to the crate statically (as all
Rust crates do 99% of the time). A detailed investigation can be found [on
github][details], but the tl;dr is that we need to stop applying dllimport so
aggressively.
This commit alters the application of dllimport on constants to only cases where
the crate the constant originated from will be linked as a dylib in some output
crate type. That way if we're just linking rlibs (like the motivation for this
issue) we won't use dllimport. For the compiler, however, (which has lots of
dylibs) we'll use dllimport.
[details]: https://github.com/rust-lang/rust/issues/26591#issuecomment-123513631
cc #26591
Makes the lint a bit more accurate, and improves the quality of the diagnostic
messages by explicitly returning an error message.
The new lint is also a little more aggressive: specifically, it now
rejects tuples, and it recurses into function pointers.
The LTO pass in the compiler forgot to call the `LLVMRustAddBuilderLibraryInfo`
function and configure other options such as merge_functions, vectorize_slp,
etc. This ended up causing linker errors on MSVC targets because the optimizer
didn't have the right knowledge that some system functions are missing on these
platforms.
This commit consolidates creation of PassManagerBuilder instances to one
function which is then called when needed. This ensures that the pass manager is
always correctly configured with the various target-specific information that
LLVM needs.
Overall, this fixes `-C lto -C opt-level=3` on 32-bit MSVC targets.
