# C++ interface function with void() signature can't be recognized by blueprint

**URL:** <https://forums.unrealengine.com/t/c-interface-function-with-void-signature-cant-be-recognized-by-blueprint/460161>\
**Category:** Blueprint\
**Tags:** unreal-engine, CPP, Blueprint, question, function-signature\
**Created:** [January 3, 2020, 3:34pm UTC](https://forums.unrealengine.com/t/c-interface-function-with-void-signature-cant-be-recognized-by-blueprint/460161 "2020-01-03T15:34:11Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![anonymous\_user\_2f169c1d1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_2f169c1d1](https://forums.unrealengine.com/u/anonymous_user_2f169c1d1)\
**Post date:** [January 3, 2020, 3:34pm UTC](https://forums.unrealengine.com/t/c-interface-function-with-void-signature-cant-be-recognized-by-blueprint/460161/1 "2020-01-03T15:34:11Z")

</div>

for example

```
class XXX_API ITargetable
{
	GENERATED_BODY()

public:

	UFUNCTION(BlueprintCallable,BlueprintNativeEvent)
	void OnTargeted();
};

```

if I create a blueprint actor implement the interface, I can’t find the function `OnTargeted()` in the `Interfaces` section

So I have to change `void OnTargeted()` to `bool OnTargeted()` now The Blueprint can recognized it now.

Is this a bug?

---

<div class="post-metadata">

**Author:** ![JoSf](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@JoSf](https://forums.unrealengine.com/u/JoSf)\
**Post date:** [January 3, 2020, 5:32pm UTC](https://forums.unrealengine.com/t/c-interface-function-with-void-signature-cant-be-recognized-by-blueprint/460161/2 "2020-01-03T17:32:29Z")

</div>

Functions without return values (void) will be implemented as Events rather than as functions. This is the behaviour with both blueprint interfaces and C++ interfaces which have been extended to blueprints.

Use the right click menu in the BP graph and search for the event by name.