What is the role of the `return` type in a function declaration?

The role of the return type in a function declaration is to specify the value type that the function will return after execution. This is a crucial element of function declarations in C++ because it informs the compiler (and the programmer) what kind of data to expect when the function is called. For example, if a function has a return type of int, it indicates that upon completion, the function will provide an integer value. This helps in ensuring type safety in programming, as it enables proper handling of the returned data and allows for better readability and maintenance of the code.

Functions can also have a return type of void, which means they do not return any value. However, when a specific data type is declared, it helps to define the behavior and usage of the function clearly. Understanding the return type also aids in debugging and understanding the logic flow of a program, especially in larger and more complex codebases.