Some user-made C functions and their D equivalents

[pascal111 via Digitalmars-d-learn]

I made a library of some useful functions while I was studying C, 
and I'm curious to know if D has equivalents or some ones for 
some of my functions, or I have to retype 'em again in D.

The library link:
https://github.com/pascal111-fra/turbo-c-programs/blob/main/COLLECT2.H