rustdoc prints types in traits different than rustc

[RalfJung]

The syntax that rustdoc uses to refer to types declared internally within a trait ("associated types"), is different from what rustc expects. This is fairly confusing for a newbie, who tries to learn the language by example - in particular, by looking at how the standard API does things.

For example, the documentation of the Iterator trait http://doc.rust-lang.org/std/iter/trait.Iterator.html refers to the type "Item" simply by "Item", but I have to write "Self::Item" for this code to actually compile.

[tomjakubowski]

This is a dupe of #21445, sort of (see #21145 (comment)).

In any case this specific aspect of #21445 will be closed by #21999.

[alexcrichton]

Closing as a dupe of #21145