Rollup merge of #128376 - compiler-errors:finish-ur-vegetables, r=jieyouxu

Mark `Parser::eat`/`check` methods as `#[must_use]`

These methods return a `bool`, but we probably should either use these values or explicitly throw them away (e.g. when we just want to unconditionally eat a token if it exists).

I changed a few places from `eat` to `expect`, but otherwise I tried to leave a comment explaining why the `eat` was okay.

This also adds a test for the `pattern_type!` macro, which used to silently accept a missing `is` token.

1 files changed, 3 insertions, 2 deletions

diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index a242dc5cd58..a4d9d97045d 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -3153,7 +3153,8 @@ impl<'a> Parser<'a> {
 
                 if !require_comma {
                     arm_body = Some(expr);
-                    this.eat(&token::Comma);
+                    // Eat a comma if it exists, though.
+                    let _ = this.eat(&token::Comma);
                     Ok(Recovered::No)
                 } else if let Some((span, guar)) =
                     this.parse_arm_body_missing_braces(&expr, arrow_span)
@@ -3654,7 +3655,7 @@ impl<'a> Parser<'a> {
                         fields.push(f);
                     }
                     self.recover_stmt_(SemiColonMode::Comma, BlockMode::Ignore);
-                    self.eat(&token::Comma);
+                    let _ = self.eat(&token::Comma);
                 }
             }
         }