From efcbf1b00bb8997f1e1ee0740640f67fbe32c615 Mon Sep 17 00:00:00 2001 From: varkor Date: Wed, 18 Nov 2020 12:49:39 +0000 Subject: Permit standalone generic parameters as const generic arguments in macros --- compiler/rustc_parse/src/parser/path.rs | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'compiler/rustc_parse/src/parser/path.rs') diff --git a/compiler/rustc_parse/src/parser/path.rs b/compiler/rustc_parse/src/parser/path.rs index 79e73749038..d64fd59b0a6 100644 --- a/compiler/rustc_parse/src/parser/path.rs +++ b/compiler/rustc_parse/src/parser/path.rs @@ -489,6 +489,7 @@ impl<'a> Parser<'a> { /// - An expression surrounded in `{}`. /// - A literal. /// - A numeric literal prefixed by `-`. + /// - A single-segment path. pub(super) fn expr_is_valid_const_arg(&self, expr: &P) -> bool { match &expr.kind { ast::ExprKind::Block(_, _) | ast::ExprKind::Lit(_) => true, @@ -496,6 +497,13 @@ impl<'a> Parser<'a> { ast::ExprKind::Lit(_) => true, _ => false, }, + // We can only resolve single-segment paths at the moment, because multi-segment paths + // require type-checking: see `visit_generic_arg` in `src/librustc_resolve/late.rs`. + ast::ExprKind::Path(None, path) + if path.segments.len() == 1 && path.segments[0].args.is_none() => + { + true + } _ => false, } } -- cgit 1.4.1-3-g733a5