Multiple root_type in one IDL file

[Andrey Upadyshev]

Hello!

When I add more than one root_type declaration, the compiler generates special functions (GetXXX etc) for last root type only.
Is it a bug?

Thank you,
Andrey

[Wouter van Oortmerssen]

It's a bug in the sense that it should give an error. A single file can only have one root type.

You can still use the other types as root types if you want by calling the templated GetRoot<> function, however.

I should document this better.

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[Andrey Upadyshev]

Hello Wouter,

Is there a significant reason for limitation to have only one root_type per file? Probably it's better to allow to have multiple root_types because otherwise protocol definition must be spread into several files (or don't use helper functions at all).

Best Regards,
Andrey

[Wouter van Oortmerssen]

the root_type is mainly for use with JSON, since there you need to know what the root type is to be able to parse it. Like I said, in C++ you don't really need the generated helper functions, you can use GetRoot<> on any type.

[Andrey Upadyshev]

Using of GetRoot<> is OK for me.

I just want to point to some inconsistency: if root_type is not important and everything can be done without using of it, why to have it at all? And if it required for something (I can not realize what it can be) then why restrict the ability to define more then one root object in one FBS file. If there is more than one root_object defined then user can just pick up one it needs in every specific case.

Best Regards