Merely because the "assert" wording is more familiar to more Rust developers because it's similar to typical test code, and can create better error messages wit

Merely because the "assert" wording is more familiar to more Rust developers because it's similar to typical test code, and can create better error messages with details. For what you're asking, the assertables crate has a macro that will handle any condition: assert_as_result!(condition) -> Result And you can alias it as you wish such as: use assertables::assert_as_result as precondition; And now you can write what you're suggesting: precondition(a == b)