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Function declared without variable name in examples

asked 2018-02-16 06:55:08 -0500

Crapsy gravatar image

Hello, I'm looking at some example provided by OpenCV and I see a recurrent typo that I don't fully understand. For instance, the erosion function in "Eroding and Dilating" example is declared:

void Erosion( int, void* );

Why do they use int and void* without variable name? And to what variable does it refer?

Thank you in advance

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supra56 gravatar imagesupra56 ( 2018-02-16 20:12:29 -0500 )edit

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answered 2018-02-16 07:08:46 -0500

berak gravatar image

it is a callback function for trackbars , its parameters are the trackbar value, and a pointer to some user supplied data.

in the example, those arguments are never used, so their names are omitted, to avoid an "unused argument" warning.

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Thank you, I couldn't expect a better answer.

Crapsy gravatar imageCrapsy ( 2018-02-16 07:26:05 -0500 )edit

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Last updated: Feb 16 '18