I'm trying to implement a for_each method for my personal script array, but I don't know how to properly write its declaration for RegisterObjectMethod. I have tried to write declaration like void for_each(void (const T&in)@ fn) or void for_each(void(@)(const T&in)) but it didn't work.

My current workaround is to register it as void for_each(?&in) and then handle the type information inside a wrapper. But my implementation has some problem. It can only accept a normal function. Once I pass a delegate, it explodes with segfault.

Link to my code for the wrapper

So my question is 1. how to register a templated funcdef, or 2. if a templated funcdef is not supported, how to write a function with ?&in parameter that handles the input correctly?

Update:

It seems that the cause of my second question is that my wrapper need to check for asTYPEID_OBJHANDLE and then dereference the pointer twice (*(void**)ptr).

Additional question: is there any document clarifying when to dereference pointer for the second time in C++ side?

You can register funcdefs as part of your template.

It looks like I've overlooked documenting this in the manual. But you can see it in practice on the scriptarray add-on and the sort method that takes a funcdef.

	// Sort with callback for comparison
	r = engine->RegisterFuncdef("bool array<T>::less(const T&in if_handle_then_const a, const T&in if_handle_then_const b)");
	r = engine->RegisterObjectMethod("array<T>", "void sort(const less &in, uint startAt = 0, uint count = uint(-1))", asMETHODPR(CScriptArray, Sort, (asIScriptFunction*, asUINT, asUINT), void), asCALL_THISCALL); assert(r >= 0);

As for the second question. The structure of the typeid is explained here: https://angelcode.com/angelscript/sdk/docs/manual/doc_typeid.html

I'll take your questions as a cue to improve the manual around these topics.

I encountered a strange issue. Once I registered a funcdef inside my custom array, the script using array<string> begin to crash. Those scripts and custom string worked fine before a funcdef registered. I can confirm this by using git reset.

I debugged into the code and found after registering the funcdef of array<T>, the constructor of my custom string wasn't properly called.

EDIT:

After debugging, I found a more precise cause. Once I registered a funcdef, the ti->GetSubTypeId() & asOBJ_REF now evaluates to true, which make my list factory of array<T> jump into wrong branch for construction. My custom string class is registered as a value type.

EDIT 2:

Sorry. It seems that I have made some silly mistakes. I mixed up type id and flags in a same variable.

@WitchLord So can you add an API like RegisterObjectFuncdef(const char* name, const char* decl) in the future version? After that, the code can be written as RegisterObjectFuncdef("array<T>", “void somefuncdef()”), which is much clearer. If nested typedef is also supported, a RegisterObjectTypedef(const char* name, const char* type, const char* decl) can be added as well.

Besides, it can make it easier to implement a template register helper like the one I'm currently working on (current solution is parsing the funcdef string and insert the class-name:: in front of the funcdef name).

I'll consider it.

Perhaps instead of adding another method to the interface, I can add an optional parameter “childOf” to RegisterFuncDef instead.