C Plus Plus 20

A post from a fill at the sonor source blog. This is dernizing your code with c plus plus 20. And some of the new ntriers they have here aree, really nice. The not always auto one i had no idea,. cas i had never tried to do this before that in a generic lamda., you could do type of previous argument, i didn't know that that would compile. It's just, it's good stuff like span.