TypeScript: The humble function overload

With the most recent type system features like conditional types or variadic tuple types, one technique to describe a function’s interface has faded into the background: Function overloads. And there’s a good reason for that. Both features have been implemented to deal with the shortcomings of regular function overloads. See this concatenation example directly from the TypeScript 4.0 release notes

[jay-es]

引数同士や戻り値の組み合わせがユニオンでは正確に表現できない場合にオーバーロードを使う