diff options
Diffstat (limited to 'compiler/rustc_parse/src/lexer/mod.rs')
| -rw-r--r-- | compiler/rustc_parse/src/lexer/mod.rs | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/compiler/rustc_parse/src/lexer/mod.rs b/compiler/rustc_parse/src/lexer/mod.rs index f50e8a8db01..b694217b58a 100644 --- a/compiler/rustc_parse/src/lexer/mod.rs +++ b/compiler/rustc_parse/src/lexer/mod.rs @@ -500,7 +500,10 @@ impl<'a> StringReader<'a> { FatalError.raise() } - // See RFC 3101. + // RFC 3101 introduced the idea of (reserved) prefixes. As of Rust 2021, + // using a (unknown) prefix is an error. In earlier editions, however, they + // only result in a (allowed by default) lint, and are treated as regular + // identifier tokens. fn report_reserved_prefix(&self, start: BytePos) { let prefix_span = self.mk_sp(start, self.pos); let msg = format!("prefix `{}` is unknown", self.str_from_to(start, self.pos)); |