Answers

1. This is because a String is essentially a pointer to Vec<u8> with some metadata. If we copy this, then we will have multiple unconstrained pointers to the same string literal, which will introduce errors with concurrency, mutability, and lifetimes.
2. We can use an Enum, which means that the type being accepted into the container can be one of those types housed in the Enum. When reading the data, we can then use a match statement to manage all possible data types that could be read from the container. The second way is to create a trait that multiple different structs implement. However, the only interaction that we can have from the container read when this is the case is the functions that the trait implements.
3. They both wrap around the code and alter the implementation or attributes of the code that they are wrapping without directly returning anything.
4. The Python equivalent is if __name__ == "__main__":.
5. A signed integer must accommodate positive and negative values, whereas an unsigned integer only accommodates positive values.
6. This is because there is no garbage collection; as a result, variables get deleted when they shift out of the scope of where they were created. If we do not consider lifetimes, we could reference a variable that has been deleted.
7. No, the ownership of the variable has essentially been moved and there are no references to the original variable anymore.
8. We can still copy and borrow the original variable; however, we cannot perform a mutable borrow.
9. We cannot use the original variable at all as the state of the variable might be altered.