std::convert docs mention the "to" convention, but don't implement it

[shepmaster]

The std::convert docs say:

They follow the standard Rust conventions of as/to/into/from.

(emphasis mine)

However, there isn't a To trait, and none of AsMut / AsRef / From / Into implement a to method. Not sure if this is a typo or an oversight resulting in a missing trait.

[steveklabnik]

Typo, I think. /cc @aturon

[shepmaster]

I'd guess that Into<Foo> for &Bar is really the equivalent of the old Bar::to_foo(&self), while Into<Foo> for Bar is the equivalent of Bar::into_foo(self). If correct, maybe that's what can be added somewhere.

[aturon]

Yes, this comment was left in from the initial implementation, which included To.

What we found eventually was that bounding by To doesn't make a lot of sense; as @shepmaster points out, Into can cover both the to and into-style conversions, and using Into instead gives the caller more flexibility (since they can pass in an owned object of the target type, or one that requires conversion).