Currently, if all the symbols in a crate have already been privately imported via use foo::*, it is not possible to publicly re-export any of them via pub use foo::Bar.
The use case where this comes up is in writing a wrapper library. All of the code will be dealing with types and functions from one crate, so it is desirable to wildcard-import everything. However, it may also be necessary to re-export some of those types, which is currently not possible.
In code, it would be nice if this worked:
use foo::*;
pub use foo::Bar;
Whereas currently it fails with error: a type named 'Bar' has already been imported in this module [E0252].