diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs index cd56d73e7d47b..b2fac7228272a 100644 --- a/src/librustdoc/html/render/mod.rs +++ b/src/librustdoc/html/render/mod.rs @@ -1276,6 +1276,15 @@ fn notable_traits_decl(decl: &clean::FnDecl, cx: &Context<'_>) -> String { if let Some((did, ty)) = decl.output.as_return().and_then(|t| Some((t.def_id(cx.cache())?, t))) { + // Box has pass-through impls for Read, Write, Iterator, and Future when the + // boxed type implements one of those. We don't want to treat every Box return + // as being notably an Iterator (etc), though, so we exempt it. Pin has the same + // issue, with a pass-through impl for Future. + if Some(did) == cx.tcx().lang_items().owned_box() + || Some(did) == cx.tcx().lang_items().pin_type() + { + return "".to_string(); + } if let Some(impls) = cx.cache().impls.get(&did) { for i in impls { let impl_ = i.inner_impl(); diff --git a/src/test/rustdoc/doc-notable_trait_box_is_not_an_iterator.rs b/src/test/rustdoc/doc-notable_trait_box_is_not_an_iterator.rs new file mode 100644 index 0000000000000..3fb00c7db8411 --- /dev/null +++ b/src/test/rustdoc/doc-notable_trait_box_is_not_an_iterator.rs @@ -0,0 +1,38 @@ +#![feature(doc_notable_trait)] +#![feature(lang_items)] +#![feature(no_core)] +#![no_core] +#[lang = "owned_box"] +pub struct Box; + +impl Box { + pub fn new(x: T) -> Box { + Box + } +} + +#[doc(notable_trait)] +pub trait FakeIterator {} + +impl FakeIterator for Box {} + +#[lang = "pin"] +pub struct Pin; + +impl Pin { + pub fn new(x: T) -> Pin { + Pin + } +} + +impl FakeIterator for Pin {} + +// @!has doc_notable_trait_box_is_not_an_iterator/fn.foo.html '//*' 'Notable' +pub fn foo(x: T) -> Box { + Box::new(x) +} + +// @!has doc_notable_trait_box_is_not_an_iterator/fn.bar.html '//*' 'Notable' +pub fn bar(x: T) -> Pin { + Pin::new(x) +}