In a mixed type expression, the compiler will attempt to promote smaller types to the larger type. So, a char or a short can be used in an expression where an int is needed because it can be promoted to the larger type with no loss of data.
Consider a function declared as taking a parameter that is an int:
void f(int i);
We can write:
short s = 42; f(s); // s is promoted to int
Here the variable s is silently converted to an int. There are some cases that may appear odd:
bool b = true; f(b); // b is promoted to int
Again, the conversion is silent. The compiler assumes you know what you are doing and that your intention is that you want false treated as 0 and true treated as 1.
