Type Alias FormatValue<Codecs, Spec>

FormatValue: (
    Selected<Codecs, Spec> extends infer Contract
        ? Contract extends FormatContract
            ? (value: Contract["value"]) => void
            : never
        : never
) extends (value: infer Value) => void
    ? Value
    : never

Value accepted for a specification by a formatter's codec tuple.

For union specifications, the result is safe for every possible selected presentation rather than a permissive union of their input values.