C++ Brain Teasers: Exercise Your Mind/

...

/

Discussion: A Strong Point

Discussion: A Strong Point

Execute the code to understand the output and gain insights into strong typing and implicit conversions.

We'll cover the following...

Run the code

Now, it’s time to execute the code and observe the output.

Press + to interact
#include <iostream>
struct Points
{
    Points(int value) : value_(value) {}
    int value_;
};
struct Player
{
    explicit Player(Points points) : points_(points) {}
    Points points_;
};
int main()
{
    Player player(3);
    std::cout << player.points_.value_;
}

Strong typing

The Player struct has a points_ member to keep track of the player’s points. Instead of using a fundamental type like int for this, we use a custom type Points. This technique is often called strong typing and can make the code easier to read and avoid bugs.

Benefits of strong typing

For instance, given a do_something(int player_id, int points, int lives) function, it can be easy to slip up and pass it player_id, lives, points instead, causing the number of lives to be used for points and vice versa. When we use separate strong types for these values, a mistake like this would cause the program to fail to compile rather than create a bug.

Understanding the output

The question in this puzzle is ...