<pre><code class="cpp">extern void f( unsigned int

extern void f( unsigned int );
extern void f( int );
extern void f( char );

int main() {
    unsigned char uc;
    f( uc );
    return 0;
}

Which variant of the overloaded function f will be called?
(provided that unsigned char occupies 1 byte and int occupies 4 bytes)

Explanation

The void f( int ) function will be called because its formal parameter provides the best match to the type of the actual parameter, since unsigned char is converted to int by type extension, and unsigned int and char by standard type conversion.