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.