Parameter Passing

Given the following (partial) class definitions:

Variant A

class Person
{
public:
    Person(std::string firstname,
           std::string lastname);
};

Variant B

class Person
{
public:
    Person(const std::string& firstname,
           const std::string& lastname);
};

Question 1: Which One Is Better?

Which of these class definitions would lead to better performance in object initialization?

Variant A	Variant B

Question2: Why?

Why does the chosen variant perform better? (Write an X in the “True” or “False” columns)

True	False	Statement
		Variant A has a shorter calling sequence
		Variant A is better at moving the parameters into the object
		Variant B does not create temporary copies