Скачать или смотреть Free Arduino library BasicOptional tutorial

I have written a version of std::optional called BasicOptional for the Arduino and I'm giving it away. If you want the library, here is a link:

https://1drv.ms/u/s!AoticBc4xuQQgTdeg...

My version implements some of the functions used on the 'optional' standard library in C++ but I may come back to this and expand upon it.
This is useful for functions that can either return something or fail to for example, you could have a function that converts string to a number. If the string is corrupted, it could return a 0 or a -1 but these are also valid numbers that could be in the string so what can we do in this scenario?
The Arduino does not have exception handling so an error cannot be reported. What you can do is return a ‘BasicOptional’ which contains the number or it is empty. You can run code if a number is contained within or you could supply your own default number if the function couldn’t decode the string.

The ‘optional’ class is used in C++17.