error missing-annotation

Публичная функция должна указывать типы параметров и результата.

What it means#

Parameter types and return types of pub and pub(api) functions MUST be written out (§3). Only private functions may omit the return type and let it be inferred from a body of the form => e.

Example#

pub fn add(a: i32, b: i32) => a + b      // <- missing-annotation (no return type)

missing-annotation

How to fix#

pub fn add(a: i32, b: i32) -> i32 => a + b

Write the return type (and parameter types) explicitly. For pub(api) functions effects must be declared as well (effects).

See also#

• cannot-infer
• private-in-public
• effects