C++: What does this code do? foo([](){bar();});

Question

I just came across a piece of that I am not able to properly look up on Google. It basically looks like this foo([](){bar();}). Here is what I actually found:

ArduinoOTA.onStart([]() {
    Serial.println("Start");
});

Could someone explain this syntax to me or at least tell me what I'm looking at here?

Thanks for marking this. I really hate myself for no having known about lambda functions before. They seem to be ridiculously useful. — Forivin, Sep 26 '16 at 19:30

score 1 · Answer 1 · answered Sep 26 '16 at 19:18

1

It just invokes some function foo with lambda function []() { bar(); } as its argument.

answered Sep 26 '16 at 19:18

Edgar Rokjān

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score 1 · Accepted Answer · answered Sep 26 '16 at 19:18

1

You're looking for lambda expressions.

In this case, it seems to be registering an action to be performed on start.

answered Sep 26 '16 at 19:18

krzaq

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C++: What does this code do? foo([](){bar();});

2 Answers2