Make `unexpected` always "return" `PResult<()>` & add `unexpected_any`

This prevents breakage when `?` no longer skews inference.

1 files changed, 12 insertions, 2 deletions

diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index 12879dc429b..125e77d8ee7 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -465,7 +465,9 @@ impl<'a> Parser<'a> {
         matches!(self.recovery, Recovery::Allowed)
     }
 
-    pub fn unexpected<T>(&mut self) -> PResult<'a, T> {
+    /// Version of [`unexpected`](Parser::unexpected) that "returns" any type in the `Ok`
+    /// (both those functions never return "Ok", and so can lie like that in the type).
+    pub fn unexpected_any<T>(&mut self) -> PResult<'a, T> {
         match self.expect_one_of(&[], &[]) {
             Err(e) => Err(e),
             // We can get `Ok(true)` from `recover_closing_delimiter`
@@ -474,6 +476,10 @@ impl<'a> Parser<'a> {
         }
     }
 
+    pub fn unexpected(&mut self) -> PResult<'a, ()> {
+        self.unexpected_any()
+    }
+
     /// Expects and consumes the token `t`. Signals an error if the next token is not `t`.
     pub fn expect(&mut self, t: &TokenKind) -> PResult<'a, Recovered> {
         if self.expected_tokens.is_empty() {
@@ -1278,7 +1284,11 @@ impl<'a> Parser<'a> {
     }
 
     fn parse_delim_args(&mut self) -> PResult<'a, P<DelimArgs>> {
-        if let Some(args) = self.parse_delim_args_inner() { Ok(P(args)) } else { self.unexpected() }
+        if let Some(args) = self.parse_delim_args_inner() {
+            Ok(P(args))
+        } else {
+            self.unexpected_any()
+        }
     }
 
     fn parse_attr_args(&mut self) -> PResult<'a, AttrArgs> {