Blueprint Map "find" node that gets value as reference possible? Same as "Get (ref)" for arrays

[DarkiRuiz]

@k_a_s_s_k_a_s_s

After some time trying it out, realized there is also a [FONT=courier new]P_GET_TMAP_REF(KeyType,ValueType,ParamName) macro. However it does require known types of key and value, while the node should work with any value/key type, so I am not sure it it’s possible to use it in a wildcard node - there seems to not ever be a complete type in the function defintion for the native [FONT=courier new]Map_Find, instead they are passed as [FONT=courier new]int32& and somehow evaluated later with [FONT=courier new]Cast<UMapProperty>…

I’m interested in this because I’ve been looking for something similar, but after reading what you posted I wonder…

From what (little) I’ve gathered about CustomThunk functions, that part before [FONT=courier new]P_FINISH is meant to be used to identify the pin type, so couldn’t you do something like… [FONT=courier new]P_GET_TMAP_REF(FProperty,FProperty,ParamName) (since all pins are “properties”), and later identify the types? Not sure if that would actually work.

@k_a_s_s_k_a_s_s

Plus another question I can’t find an answer to: Is there also a way to return a value by ref in a K2 node? Can’t seem to figure it out, any [FONT=courier new]& parameters in the function definition seem to be returned by value - the pin is circular and modifying that value doesn’t update it in the map…

Er, isn’t “returning a value by ref” kind of incongruous here? I’m talking from my knowledge of C++ limited to mainly UE4 itself, so maybe what I say it’s possible in plain C++ but the reflection system doesn’t support it. Otherwise I suppose you’d simply need to make the return type of the function itself by ref, something like this:

 UFUNCTION(BlueprintCallable, CustomThunk, meta = (MapParam = "TargetMap", MapKeyParam = "Key")
int32& Map_FindRef(const TMap<int32, int32>& TargetMap, const int32& Key);