How does cin evaluate to true when inside an if statement?

Question

I thought that:

if (true) 
{execute this statement}

So how does if (std::cin >> X) execute as true when there is nothing

Answer 1

if(x) is equivalent to if(bool(x))

in this case bool(x) calls std::istream::operator bool(x)

this will return:

true if none of failbit or badbit is set.

false otherwise.