more strongly dissuade use of skip_binder
#144775
Merged
+30
−30
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
rustbot
added
S-waiting-on-review
lcnr
force-pushed
the
skip_binder-comment
branch
from
78b4cd0 to
fc46354
Compare
fmease
reviewed
Aug 1, 2025
Comment on lines
+159
to
+161
| /// Please read <https://rustc-dev-guide.rust-lang.org/ty_module/instantiating_binders.html> | ||
| /// before using this function. It is usually better to discharge the binder using | ||
| /// `no_bound_vars` or `instantiate_bound_regions` or something like that. |
There was a problem hiding this comment.
Consider wrapping this and maybe its following paragraphs in a big warning block by surrounding it with <div class="warning"> </div> (note: there needs to be a blank line between the HTML tags and the Markdown content or else the latter would be interpreted as HTML), similarly for the EarlyBinder case.
These get rendered like so: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.TyCtxt.html#method.expand_free_alias_tys
There was a problem hiding this comment.
Hm, I feel I'd need to already mark the "Accessing generic args in the returned value is generally incorrect." as a warning, but that's part of the first line.
I personally don't know how I'd restructure this to add a warning block and would merge this as is
|
@bors r+ rollup I agree it'd be nice to have an actual warning here 🤔 but not sure how to structure this to do that nicely. can always do that in a follow up PR |
bors
added
S-waiting-on-bors
bors
added a commit
that referenced
this pull request
Aug 8, 2025
Rollup of 8 pull requests Successful merges: - #139451 (Add `target_env = "macabi"` and `target_env = "sim"`) - #144039 (Use `tcx.short_string()` in more diagnostics) - #144192 (atomicrmw on pointers: move integer-pointer cast hacks into backend) - #144545 (In rustc_pattern_analysis, put `true` witnesses before `false` witnesses) - #144579 (Implement declarative (`macro_rules!`) attribute macros (RFC 3697)) - #144649 (Account for bare tuples and `Pin` methods in field searching logic) - #144775 (more strongly dissuade use of `skip_binder`) - #144987 (Enable f16 and f128 on targets that were fixed in LLVM21) r? `@ghost` `@rustbot` modify labels: rollup
rust-timer
added a commit
that referenced
this pull request
Aug 9, 2025
Rollup merge of #144775 - lcnr:skip_binder-comment, r=BoxyUwU more strongly dissuade use of `skip_binder` People unfortunately encounter `Binder` and `EarlyBinder` very early on when starting out. In these cases its often very easy to use `skip_binder` incorrectly. This makes it more explicit that it should generally not be used and points to the relevant `rustc-dev-guide` chapters. r? `@BoxyUwU`
github-actions bot
pushed a commit
to rust-lang/miri
that referenced
this pull request
Aug 9, 2025
Rollup of 8 pull requests Successful merges: - rust-lang/rust#139451 (Add `target_env = "macabi"` and `target_env = "sim"`) - rust-lang/rust#144039 (Use `tcx.short_string()` in more diagnostics) - rust-lang/rust#144192 (atomicrmw on pointers: move integer-pointer cast hacks into backend) - rust-lang/rust#144545 (In rustc_pattern_analysis, put `true` witnesses before `false` witnesses) - rust-lang/rust#144579 (Implement declarative (`macro_rules!`) attribute macros (RFC 3697)) - rust-lang/rust#144649 (Account for bare tuples and `Pin` methods in field searching logic) - rust-lang/rust#144775 (more strongly dissuade use of `skip_binder`) - rust-lang/rust#144987 (Enable f16 and f128 on targets that were fixed in LLVM21) r? `@ghost` `@rustbot` modify labels: rollup
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
People unfortunately encounter
BinderandEarlyBindervery early on when starting out. In these cases its often very easy to useskip_binderincorrectly. This makes it more explicit that it should generally not be used and points to the relevantrustc-dev-guidechapters.r? @BoxyUwU