Rollup merge of #61409 - varkor:condition-trait-param-ice, r=oli-obk

Fix an ICE with a const argument in a trait

This goes some way towards fixing https://github.com/rust-lang/rust/issues/61383 (the reduced test case is fixed).

1 files changed, 7 insertions, 3 deletions

diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index f200d3ec8d5..671b313c7f2 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -5244,9 +5244,13 @@ impl<'a> Parser<'a> {
                     // FIXME(const_generics): to distinguish between idents for types and consts,
                     // we should introduce a GenericArg::Ident in the AST and distinguish when
                     // lowering to the HIR. For now, idents for const args are not permitted.
-                    return Err(
-                        self.fatal("identifiers may currently not be used for const generics")
-                    );
+                    if self.token.is_keyword(kw::True) || self.token.is_keyword(kw::False) {
+                        self.parse_literal_maybe_minus()?
+                    } else {
+                        return Err(
+                            self.fatal("identifiers may currently not be used for const generics")
+                        );
+                    }
                 } else {
                     self.parse_literal_maybe_minus()?
                 };