Commit c58fe21

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Handle parenthesised infer args

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+32

-6

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+32

-6

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Lines changed: 9 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -288,6 +288,7 @@ impl ParenthesizedArgs {`
`288`	`288`	`}`
`289`	`289`	`}`
`290`	`290`
	`291`	`+use crate::AstDeref;`
`291`	`292`	`pub use crate::node_id::{CRATE_NODE_ID, DUMMY_NODE_ID, NodeId};`
`292`	`293`
`293`	`294`	/// Modifiers on a trait bound like `~const`, `?` and `!`.
`@@ -2166,6 +2167,14 @@ impl Ty {`
`2166`	`2167`	`}`
`2167`	`2168`	`final_ty`
`2168`	`2169`	`}`
	`2170`	`+`
	`2171`	`+ pub fn is_maybe_parenthesised_infer(&self) -> bool {`
	`2172`	`+ match &self.kind {`
	`2173`	`+ TyKind::Infer => true,`
	`2174`	`+ TyKind::Paren(inner) => inner.ast_deref().is_maybe_parenthesised_infer(),`
	`2175`	`+ _ => false,`
	`2176`	`+ }`
	`2177`	`+ }`
`2169`	`2178`	`}`
`2170`	`2179`
`2171`	`2180`	`#[derive(Clone, Encodable, Decodable, Debug)]`

Lines changed: 11 additions & 6 deletions

Original file line number	Diff line number	Diff line change
`@@ -1084,17 +1084,22 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {`
`1084`	`1084`	`match arg {`
`1085`	`1085`	`ast::GenericArg::Lifetime(lt) => GenericArg::Lifetime(self.lower_lifetime(lt)),`
`1086`	`1086`	`ast::GenericArg::Type(ty) => {`
	`1087`	+ // We cannot just match on `TyKind::Infer` as `(_)` is represented as
	`1088`	+ // `TyKind::Paren(TyKind::Infer)` and should also be lowered to `GenericArg::Infer`
	`1089`	`+ if ty.is_maybe_parenthesised_infer() {`
	`1090`	`+ return GenericArg::Infer(hir::InferArg {`
	`1091`	`+ hir_id: self.lower_node_id(ty.id),`
	`1092`	`+ span: self.lower_span(ty.span),`
	`1093`	`+ });`
	`1094`	`+ }`
	`1095`	`+`
`1087`	`1096`	`match &ty.kind {`
`1088`		`- TyKind::Infer => {`
`1089`		`- return GenericArg::Infer(hir::InferArg {`
`1090`		`- hir_id: self.lower_node_id(ty.id),`
`1091`		`- span: self.lower_span(ty.span),`
`1092`		`- });`
`1093`		`- }`
`1094`	`1097`	`// We parse const arguments as path types as we cannot distinguish them during`
`1095`	`1098`	`// parsing. We try to resolve that ambiguity by attempting resolution in both the`
`1096`	`1099`	`// type and value namespaces. If we resolved the path in the value namespace, we`
`1097`	`1100`	`// transform it into a generic const argument.`
	`1101`	`+ //`
	`1102`	+ // FIXME: Should we be handling `(PATH_TO_CONST)`?
`1098`	`1103`	`TyKind::Path(None, path) => {`
`1099`	`1104`	`if let Some(res) = self`
`1100`	`1105`	`.resolver`

Lines changed: 12 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,12 @@`
	`1`	`+//@ check-pass`
	`2`	`+//@ revisions: gate nogate`
	`3`	`+#![cfg_attr(gate, feature(generic_arg_infer))]`
	`4`	`+`
	`5`	`+fn main() {`
	`6`	`+ // AST Types preserve parens for pretty printing reasons. This means`
	`7`	+ // that this is parsed as a `TyKind::Paren(TyKind::Infer)`. Generic
	`8`	+ // arg lowering therefore needs to take into account not just `TyKind::Infer`
	`9`	+ // but `TyKind::Infer` wrapped in arbitrarily many `TyKind::Paren`.
	`10`	`+ let a: Vec<(_)> = vec![1_u8];`
	`11`	`+ let a: Vec<(((((_)))))> = vec![1_u8];`
	`12`	`+}`

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