Please error, or at least warn, when a managed type is included in INetworkSerializeByMemcpy

Is your feature request related to a problem? Please describe.

My coworker was unfamiliar with INetworkSerializeByMemcpy and the FixedStringNNNBytes types, and added a string field to an existing INetworkSerializeByMemcpy struct. This caused me great headaches (it made it into a publicly released patch), trying to track down segfault heap corruption that only showed up in very specific multiplayer circumstances (the string was normally null, which probably masked the issue).

Describe the solution you'd like

Please cause a build error when a managed type (a class, a string, or the like) is included in an INetworkSerializeByMemcpy type. I cannot think of any use case where it would be valid or intended to serialize a managed GC pointer by memcpy. At least a warning if nothing else.

It doesn't have to be perfect, even just checking for string would be lovely - string specifically is such a massive footgun, it's so easy to accidentally include and think it'll work fine. The fact it crashes later on via unrelated segfault heap corruption bringing down the editor, instead of a C# Exception, is especially rough.

Bắt đầu bằng cách tìm định nghĩa INetworkSerializeByMemcpy và các bài kiểm tra xác thực hoặc tuần tự hóa của nó. Theo dõi cách các kiểu triển khai nó được kiểm tra trong quá trình biên dịch hoặc khi chạy, sau đó thêm coverage cho các trường string và những trường được quản lý khác; được xem là hoàn tất khi các kiểu như vậy tạo ra lỗi hoặc cảnh báo build thay vì tuần tự hóa memcpy không an toàn.