仓颉标准库格式化字串 Skill

导入：import std.convert.*

1. Formattable 接口

public interface Formattable {
    func format(fmt: String): String
}

已实现类型

Int8, Int16, Int32, Int64, UInt8, UInt16, UInt32, UInt64, Float16, Float32, Float64, Rune