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| -rw-r--r-- | src/doc/rustc-dev-guide/src/opaque-types-impl-trait-inference.md | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/src/doc/rustc-dev-guide/src/opaque-types-impl-trait-inference.md b/src/doc/rustc-dev-guide/src/opaque-types-impl-trait-inference.md index bdf4e4cd870..42600ad87f8 100644 --- a/src/doc/rustc-dev-guide/src/opaque-types-impl-trait-inference.md +++ b/src/doc/rustc-dev-guide/src/opaque-types-impl-trait-inference.md @@ -13,13 +13,16 @@ it can work across functions and function bodies. To help explain how it works, let's consider an example. ```rust +#![feature(type_alias_impl_trait)] mod m { pub type Seq<T> = impl IntoIterator<Item = T>; + #[define_opaque(Seq)] pub fn produce_singleton<T>(t: T) -> Seq<T> { vec![t] } + #[define_opaque(Seq)] pub fn produce_doubleton<T>(t: T, u: T) -> Seq<T> { vec![t, u] } |