error private-in-public

What it means#

A type used in the signature of a visible declaration MUST be at least as visible as the declaration itself (§2.3). Otherwise callers would have to name a type they cannot see.

Example#

data Internal { id: u64 }

pub fn make() -> Internal {      // <- private-in-public
  Internal{ id: 1 }
}

private-in-public

How to fix#

pub data Internal { id: u64 }

pub fn make() -> Internal {
  Internal{ id: 1 }
}

Make the type as visible as the function, or make the function less visible. For pub(api) functions every type in the signature must be pub(api) too.

See also#

• visibility
• missing-annotation