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Why sendGoal is called with one parameter

sendGoal

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

Raj
3 ●1 ●1 ●3

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

jayess
6155 ●26 ●85 ●92

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

flag of Czech Republic

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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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Comments

Got it. Thank you

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

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

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

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

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

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

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Last updated: Nov 06 '17

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