The purpose of the poll() and select() system calls is to perform which of the following functions?

Which of the following provides the most random seed source for a pseudo random number generator?

Which type cast preserves the mathematical value in all cases?

Which choice is not a scalar data type?

_ cannot be destructured.

Which cargo command checks a program for error without creating a binary executable?

Defining a _ requires a lifetime parameter.

In matching patterns, values are ignored with _.

Which comment syntax is not legal?

What happens when an error occurs that is being handled by the question mark (?) operator?

The smart pointers Rc and Arc provide reference counting. What is the API for incrementing a reference count?