Assuming that you want to call FileExists or a similar C++ function from your Blueprint,
This is what you should do when you want to expose a built-in function which is not available in BP to blueprint:
Create a new C++ class extended from UBlueprintFunctionLibrary. Declare a wrapper function that accepts the same parameters as the function you want to expose.
So in this case:
UFUNCTION(BlueprintPure, Category="Wrapper")
public static bool MyFileExists(const FString & InPath)
Later you define this function something like this:
bool MyFileExists(const FString & InPath) {
return FPaths::FileExists(InPath);
}
Now once you compile the code, your custom function MyFileExists will be available in all your blueprints (you might want to disable ‘ContextSensitive’).
This should be useful:
}