In this example, the only difference between the two patterns is the guard expression, but that's enough for the compiler to differentiate them.

在这个例子里，两个模式的唯一区别就是这个守卫表达式，但是这样足够编译器来区分它们了。

youdao

This case only succeeds if the accompanying guard expression (the if expression that follows it) succeeds, which will only happen for the first Person but not the second.

这个case只有在同时提供的起保护作用的表达式(跟在它后边的if表达式)成功时才会成功，但只有第一个Person会这样，第二个就不会了。

youdao