What would be a “Hello, World!” example for “std::ref”?

Question

Can somebody give a simple example which demonstrates the functionality of std::ref? I mean an example in which some other constructs (like tuples, or data type tem

Answer 1

void PrintNumber(int i) {...}

int n = 4;
std::function print1 = std::bind(&PrintNumber, n);
std::function print2 = std::bind(&PrintNumber, std::ref(n));

n = 5;

print1(); //prints 4
print2(); //prints 5

std::ref is mainly used to encapsulate references when using std::bind (but other uses are possible of course).