声明：本文来自微信公众号“深燃”（ID:shenrancaijing），作者:深燃团队，授权转载发布。
When we define our interfaces in C# 4.0, we are allowed to mark each of the generic parameters as in or out. If we try to set a generic parameter as out and that\'d lead to a problem, the compiler rai
加载中,请稍侯......