/technologies/code_exchange/b/blog/posts/c-classes-and-operatorsThis is a &quot;classic C++&quot; post, something that&#39;s been part of the language since conception: How to use an operator in your class design. I developed a callback class. Your &quot;gizmo that needs to callback something&quot; would hold an instance of that class (en-USTelligent Community 12https://community.element14.com/technologies/code_exchange/b/blog/posts/c-classes-and-operatorsSun, 09 Mar 2025 19:47:22 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:e9566ac9-093b-41ed-a91a-a02864619729Jan Cumps2<p>Here is how I used this in Raspberry Pico code, where I use a callback when i need data from UART:</p> <p></p> <p>[embed:dc8ab71f-3b98-42d9-b0f6-e21e02a0f8e2:544192ac-a28d-4462-b7a6-33a10a260723:type=csharp&text=callbackmanager%3A%3ACallback%3Cvoid%2C%20std%3A%3Astring%26%3E%20reader%3B%0A%0Areader.set%28%5B%5D%28std%3A%3Astring%26%20s%29%20-%3E%20void%20%7B%20read%28s%29%3B%20%7D%29%3B%0A%2F%2F%20read%20is%20a%20Pico%20function%20that%20gets%20all%20available%20data%20from%20the%20controller%27s%20UART%20buffer.%0A%2F%2F%20it%20stores%20the%20results%20in%20the%20std%3A%3Astring%20tht%27s%20passed%20to%20it%20as%20a%20reference.]</p> <p>In my business logic, that doesn&#39;t know anything about Pico or UART, I invoke a read by calling that callback:</p> <p>[embed:dc8ab71f-3b98-42d9-b0f6-e21e02a0f8e2:f78c1ef4-9de2-4db7-ab40-d1a5474465af:type=csharp&text=%2F%2F%20In%20my%20business%20logic%0A%0Avoid%20mybusinessclass%3A%3Aread%28std%3A%3Astring%26%20s%29%20%7B%0A%20%20%20%20reader%28s%29%3B%0A%7D]</p> <p>The callback class will call that read() function we set earlier, to get the data from the UART, and put it in std::string s.</p><img src="https://community.element14.com/aggbug?PostID=28759&AppID=74&AppType=Weblog&ContentType=0" width="1" height="1">