Question

I have a problem that similar to : this question

But I still don’t understand what is the difference between :

void test(TestInfo&)
{

}

and

void test(const TestInfo&)
{

}

Answer 1

The first passes a reference while the second passes an const reference to the function test(),
Note that const reference basically means a reference to a const data.

In the second case you cannot modify the contents of TestInfo inside the function.
Any attempt to modify the passed TestInfo object inside the function would result in a
Undefined Behavior.