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Why sendGoal is called with one parameter

asked 2017-11-02 22:13:51 -0500

Raj gravatar image

updated 2017-11-06 09:52:48 -0500

jayess gravatar image

sendGoal is defined with 4 parameters in simple_action_client.h but while using this API we call it with one parameter viz send Goal(goal). Why ?

Following is how it is defined in simple_action_client.h

void SimpleActionClient<ActionSpec>::sendGoal(const Goal& goal,
                                              SimpleDoneCallback     done_cb,
                                              SimpleActiveCallback   active_cb,
                                              SimpleFeedbackCallback feedback_cb)
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answered 2017-11-03 08:33:46 -0500

l4ncelot gravatar image

In simple_action_client.h it's defined like this:

void sendGoal(const Goal& goal,
                SimpleDoneCallback     done_cb     = SimpleDoneCallback(),
                SimpleActiveCallback   active_cb   = SimpleActiveCallback(),
                SimpleFeedbackCallback feedback_cb = SimpleFeedbackCallback());

In C++ you can specify default function argument value with = sign. It's an optional value and therefore doesn't need to be present while calling that function. If you don't specify one it will take the default value (e.g. SimpleDoneCallback()).

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Got it. Thank you

Raj gravatar image Raj  ( 2017-11-04 15:24:34 -0500 )edit

@Raj please accept the answer above with the checkmark to the left so others know it's resolved.

tfoote gravatar image tfoote  ( 2017-11-06 18:47:28 -0500 )edit

@tfoote: I guess I did it before. Sorry if I missed it.

Raj gravatar image Raj  ( 2017-11-06 19:56:45 -0500 )edit

@Raj it's still not checked. Click on the checkmark itself (it will turn green) to indicate that it's resolved.

tfoote gravatar image tfoote  ( 2017-11-06 20:52:37 -0500 )edit

@tfoote I did and it's showing green to me.

Raj gravatar image Raj  ( 2017-11-06 20:55:43 -0500 )edit

Are you sure you got the check mark and not the upvote arrow? If you mouse over it should say "mark this answer as correct"

tfoote gravatar image tfoote  ( 2017-11-07 18:30:48 -0500 )edit

@tfoote Oh My bad. Sorry as I am new user. I hope now I did it correctly

Raj gravatar image Raj  ( 2017-11-07 18:35:08 -0500 )edit

No worries, there's always a learning curve for new interfaces. I'm glad you got your question answered quickly.

tfoote gravatar image tfoote  ( 2017-11-07 18:39:17 -0500 )edit

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Asked: 2017-11-02 22:13:51 -0500

Seen: 187 times

Last updated: Nov 06 '17