f# – 使用’flexible’类型参数对泛型类型进行模式匹配

match value with
| :? list<#SomeType> as l -> l //Is it possible to match any list of a type derived from SomeType?
| _ -> failwith "doesn't match"

解决方法

不,遗憾的是不可能做这样的事情 – CLR没有提供任何有效的方式来进行这种类型的测试.有些(相当难看的)解决方案请参见 How to cast an object to a list of generic type in F#和 F# and pattern matching on generics in a non-generic method implementing an interface.