Learning how nullptr works

Before C++11, the NULL identifier was meant to be used for pointers. In this recipe, we'll see why this was a problem and how C++11 solved it.

How to do it...

To understand why nullptr is important, let's look at the problem with NULL:

1. Let's write the following code:

bool speedUp (int speed);
bool speedUp (char* speed);
int main()  
{
    bool ok = speedUp (NULL);
}

2. Now, let's rewrite the preceding code using nullptr:

bool speedUp (int speed);
bool speedUp (char* speed);
int main()  
{
    bool ok = speedUp (nullptr);
}

How it works...

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