Automated conversion using the untry tool [1] and the following command:
```
$ find -name '*.rs' -type f | xargs untry
```
at the root of the Rust repo.
[1]: https://github.com/japaric/untry
std: Change `encode_utf{8,16}` to return iterators
Currently these have non-traditional APIs which take a buffer and report how
much was filled in, but they're not necessarily ergonomic to use. Returning an
iterator which *also* exposes an underlying slice shouldn't result in any
performance loss as it's just a lazy version of the same implementation, and
it's also much more ergonomic!
cc #27784
This is a new suite of tests that verifies that the compiler
builds specific revisions of select crates from crates.io.
It does not run by default. It is intended that buildbot
runs these tests against all PRs, and gate on them.
Currently these have non-traditional APIs which take a buffer and report how
much was filled in, but they're not necessarily ergonomic to use. Returning an
iterator which *also* exposes an underlying slice shouldn't result in any
performance loss as it's just a lazy version of the same implementation, and
it's also much more ergonomic!
cc #27784
Move analysis for MIR borrowck
This PR adds code for doing MIR-based gathering of the moves in a `fn` and the dataflow to determine where uninitialized locations flow to, analogous to how the same thing is done in `borrowck`.
It also adds a couple attributes to print out graphviz visualizations of the analyzed MIR that includes the dataflow analysis results.
cc @nikomatsakis
Apparently these aren't supposed to be stored in network byte order, so doing so
ends up causing failures when it would otherwise succeed when stored in the host
byte order.
Closes#32424
Improve time complexity of equality relations
This PR adds a `UnificationTable` to the `TypeVariableTable` type which is used store information about variable equality instead of just storing them in a vector for later processing. By using a `UnificationTable` equality relations can be resolved in O(n) (for all realistic values of n) rather than O(n!) which can give massive speedups in certain cases (see combine as an example).
Link to combine: https://github.com/Marwes/combine
This PR adds a `UnificationTable` to the `TypeVariableTable` type which
is used store information about variable equality instead of just
storing them in a vector for later processing. By using a
`UnificationTable` equality relations can be resolved in O(n) (for all
realistic values of n) rather than O(n!) which can give massive
speedups in certain cases (see combine as an example).
Link to combine: https://github.com/Marwes/combine
Instead, create a single MovePathIndex that represents all statics.
(An alternative here would be to disallow representing statics at all.
I am hesitant to do that right now, in part because it could impose a
requirement that I thread checks for static data into the calling
code, either as pre- or post-invocation of `fn move_path_for`.)
emit (via debug!) scary message from `fn borrowck_mir` until basic
prototype is in place.
Gather children of move paths and set their kill bits in
dataflow. (Each node has a link to the child that is first among its
siblings.)
Hooked in libgraphviz based rendering, including of borrowck dataflow
state.
doing this well required some refactoring of the code, so I cleaned it
up more generally (adding comments to explain what its trying to do
and how it is doing it).
Update: this newer version addresses most review comments (at least
the ones that were largely mechanical changes), but I left the more
interesting revisions to separate followup commits (in this same PR).
Documentation fix for E0368
Made the 'good' example compile.
I got to the [E0368 error page](https://doc.rust-lang.org/error-index.html#E0368) by following the link in the output of the
compiler. My understanding is that the first example is 'bad' and the
second one is 'good'. Following that logic, I pasted the second example
into the file and to my surprise it did not compile. This commit fixes
the example to make it paste-able.
On the other hand the docstring contained `compile_fail` flag, which might indicate that this was intentional.
I am also assuming here that the `Rust Compiler Error Index` page is generated from the file I changed.
Please let me know what do you think. Thanks a lot !
Update of the book; Error handling, section on custom error types: we…
… should also show the changes to the `cause` method.
When I started creating my own error type, I found that we also have to update the cause method, otherwise we have a missing match branch.
It would also be nice to elaborate on the relationship and difference between the description() and fmt() method, but that should be done by someone with more experience with them. :)
