diff --git a/crates/hir-expand/src/mod_path.rs b/crates/hir-expand/src/mod_path.rs index fea09521e8..9ddafe0181 100644 --- a/crates/hir-expand/src/mod_path.rs +++ b/crates/hir-expand/src/mod_path.rs @@ -257,6 +257,7 @@ macro_rules! __known_path { (core::ops::RangeToInclusive) => {}; (core::ops::RangeInclusive) => {}; (core::future::Future) => {}; + (core::future::IntoFuture) => {}; (core::ops::Try) => {}; ($path:path) => { compile_error!("Please register your known path in the path module") diff --git a/crates/hir-expand/src/name.rs b/crates/hir-expand/src/name.rs index 47d191822d..757db79db4 100644 --- a/crates/hir-expand/src/name.rs +++ b/crates/hir-expand/src/name.rs @@ -258,6 +258,7 @@ pub mod known { Try, Ok, Future, + IntoFuture, Result, Option, Output, @@ -391,6 +392,7 @@ pub mod known { future_trait, index, index_mut, + into_future, mul_assign, mul, neg, diff --git a/crates/hir-ty/src/infer.rs b/crates/hir-ty/src/infer.rs index 46eeea0e6f..95a7229e87 100644 --- a/crates/hir-ty/src/infer.rs +++ b/crates/hir-ty/src/infer.rs @@ -875,7 +875,10 @@ impl<'a> InferenceContext<'a> { } fn resolve_future_future_output(&self) -> Option { - let trait_ = self.resolve_lang_item(name![future_trait])?.as_trait()?; + let trait_ = self + .resolver + .resolve_known_trait(self.db.upcast(), &path![core::future::IntoFuture]) + .or_else(|| self.resolve_lang_item(name![future_trait])?.as_trait())?; self.db.trait_data(trait_).associated_type_by_name(&name![Output]) } diff --git a/crates/hir-ty/src/tests/traits.rs b/crates/hir-ty/src/tests/traits.rs index 75802a5eb4..730ebe2357 100644 --- a/crates/hir-ty/src/tests/traits.rs +++ b/crates/hir-ty/src/tests/traits.rs @@ -137,6 +137,31 @@ fn not_send() -> Box + 'static> { ); } +#[test] +fn into_future_trait() { + check_types( + r#" +//- minicore: future +struct Futurable; +impl core::future::IntoFuture for Futurable { + type Output = u64; + type IntoFuture = IntFuture; +} + +struct IntFuture; +impl core::future::Future for IntFuture { + type Output = u64; +} + +fn test() { + let r = Futurable; + let v = r.await; + v; +} //^ u64 +"#, + ); +} + #[test] fn infer_try() { check_types( diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs index 8f984210e1..800ea58ba2 100644 --- a/crates/hir/src/lib.rs +++ b/crates/hir/src/lib.rs @@ -2780,6 +2780,8 @@ impl Type { /// Checks that particular type `ty` implements `std::future::Future`. /// This function is used in `.await` syntax completion. pub fn impls_future(&self, db: &dyn HirDatabase) -> bool { + // FIXME: This should be checking for IntoFuture trait, but I don't know how to find the + // right TraitId in this crate. let std_future_trait = db .lang_item(self.env.krate, SmolStr::new_inline("future_trait")) .and_then(|it| it.as_trait()); diff --git a/crates/hir/src/source_analyzer.rs b/crates/hir/src/source_analyzer.rs index f5e2e44307..756772cf84 100644 --- a/crates/hir/src/source_analyzer.rs +++ b/crates/hir/src/source_analyzer.rs @@ -269,6 +269,8 @@ impl SourceAnalyzer { db: &dyn HirDatabase, await_expr: &ast::AwaitExpr, ) -> Option { + // FIXME This should be pointing to the poll of IntoFuture::Output's Future impl, but I + // don't know how to resolve the Output type so that we can query for its poll method. let ty = self.ty_of_expr(db, &await_expr.expr()?.into())?; let op_fn = db diff --git a/crates/ide-assists/src/utils/suggest_name.rs b/crates/ide-assists/src/utils/suggest_name.rs index 779cdbc93c..68d59daef4 100644 --- a/crates/ide-assists/src/utils/suggest_name.rs +++ b/crates/ide-assists/src/utils/suggest_name.rs @@ -55,6 +55,7 @@ const USELESS_METHODS: &[&str] = &[ "iter", "into_iter", "iter_mut", + "into_future", ]; pub(crate) fn for_generic_parameter(ty: &ast::ImplTraitType) -> SmolStr { diff --git a/crates/ide-completion/src/completions/keyword.rs b/crates/ide-completion/src/completions/keyword.rs index 3989a451bd..032b23725f 100644 --- a/crates/ide-completion/src/completions/keyword.rs +++ b/crates/ide-completion/src/completions/keyword.rs @@ -75,16 +75,17 @@ impl Future for A {} fn foo(a: A) { a.$0 } "#, expect![[r#" - kw await expr.await - sn box Box::new(expr) - sn call function(expr) - sn dbg dbg!(expr) - sn dbgr dbg!(&expr) - sn let let - sn letm let mut - sn match match expr {} - sn ref &expr - sn refm &mut expr + kw await expr.await + me into_future() (as IntoFuture) fn(self) -> ::IntoFuture + sn box Box::new(expr) + sn call function(expr) + sn dbg dbg!(expr) + sn dbgr dbg!(&expr) + sn let let + sn letm let mut + sn match match expr {} + sn ref &expr + sn refm &mut expr "#]], ); @@ -98,18 +99,19 @@ fn foo() { } "#, expect![[r#" - kw await expr.await - sn box Box::new(expr) - sn call function(expr) - sn dbg dbg!(expr) - sn dbgr dbg!(&expr) - sn let let - sn letm let mut - sn match match expr {} - sn ref &expr - sn refm &mut expr + kw await expr.await + me into_future() (use core::future::IntoFuture) fn(self) -> ::IntoFuture + sn box Box::new(expr) + sn call function(expr) + sn dbg dbg!(expr) + sn dbgr dbg!(&expr) + sn let let + sn letm let mut + sn match match expr {} + sn ref &expr + sn refm &mut expr "#]], - ) + ); } #[test] diff --git a/crates/test-utils/src/minicore.rs b/crates/test-utils/src/minicore.rs index f48d1ec66a..6df29db474 100644 --- a/crates/test-utils/src/minicore.rs +++ b/crates/test-utils/src/minicore.rs @@ -471,6 +471,21 @@ pub mod future { #[lang = "poll"] fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll; } + + pub trait IntoFuture { + type Output; + type IntoFuture: Future; + #[lang = "into_future"] + fn into_future(self) -> Self::IntoFuture; + } + + impl IntoFuture for F { + type Output = F::Output; + type IntoFuture = F; + fn into_future(self) -> F { + self + } + } } pub mod task { pub enum Poll {