Items must show what paths they make available.

[Havvy]

Every item should declare what paths it adds. We can say that the canonical path for an item is its path prefix followed by :: followed by the item's path component. Modules and implementations change the path prefix, while everything except implementations define new path components.

• [ ] constants
• [ ] enumerations
• [ ] extern crates
• [ ] external blocks
• [ ] functions
• [ ] implementations
• [ ] modules
• [ ] statics
• [ ] structs
• [ ] traits
• [ ] type aliases
• [ ] unions
• [ ] use declarations

[ehuss]

Posted #1052 with what I think should close this out.