Item 20: Prefer pass-by-reference-to-const to pass-by-value(Effective C++)
Prefer pass-by-reference-to-const over pass-by-value. It's typically more efficient and it avoids the slicing problem.
The rule doesn't apply to built-in types and STL iterator and function object types. For them, pass-by-value is usually appropriate.
The rule doesn't apply to built-in types and STL iterator and function object types. For them, pass-by-value is usually appropriate.
