Which choice is not a scalar data type?

_ cannot be destructured.

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

The term box and related phrases such as boxing a value are often used when relating to memory layout. What does box refer to?

Using the ? operator at the end of an expression is equivalent to _.

Which is valid syntax for defining an array of i32 values?

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?