C++ Tutorial/Function/overloading ambiguity
Версия от 14:21, 25 мая 2010; (обсуждение)
Содержание
Overloading abiguity: default parameter
#include <iostream>
using namespace std;
int f(int i);
int f(int i, int j=1);
int main()
{
cout << f(4, 5) << " "; // unambiguous
//cout << f(10); // Error, ambiguous!
return 0;
}
int f(int i)
{
return i;
}
int f(int i, int j)
{
return i*j;
}20
Overloading a function - removing ambiguity with a cast
#include <iostream>
using std::cout;
using std::endl;
double larger(double a, double b);
long larger(long a, long b);
int main() {
int a_int = 15, b_int = 25;
cout << larger(static_cast<long>(a_int), static_cast<long>(b_int))
<< endl;
return 0;
}
double larger(double a, double b) {
cout << "double larger() called" << endl;
return a>b ? a : b;
}
long larger(long a, long b) {
cout << "long larger() called" << endl;
return a>b ? a : b;
}long larger() called 25
Overloading ambiguity: char and unsigned char
#include <iostream>
using namespace std;
char f(unsigned char ch);
char f(char ch);
int main()
{
cout << f("c"); // this calls f(char)
//cout << f(88) << " "; // Error, ambiguous!
return 0;
}
char f(unsigned char ch)
{
return ch-1;
}
char f(char ch)
{
return ch+1;
}d
Overloading ambiguity: float and double
#include <iostream>
using namespace std;
float f(float i);
double f(double i);
int main()
{
// unambiguous, calls f(double)
cout << f(10.1) << " ";
// ambiguous
//cout << f(10); // Error!
return 0;
}
float f(float i)
{
return i;
}
double f(double i)
{
return -i;
}-10.1
