Pointers present some special problems for overload resolution.
Say for example,
void f(int* x) { ... }
void f(char* x) { ...}
int main()
{
f(0);
}
What is wrong with calling f(0)? How can I fix the function call for f(0)?
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240answers:
3
+6
A:
f((int*) 0) or f((char *) 0)
But if you find yourself doing this I would take another look at your design.
Mitch Wheat
2009-03-13 00:39:44
Is it because chars are represented as numbers or?
2009-03-13 00:40:54
It is because you can't infer the type from just a zero
Mitch Wheat
2009-03-13 00:41:55
0 means null pointer in C++. So it could be a null int* or a null char*. Compiler can't determine which one.
Michael
2009-03-13 00:42:03
Technically, it's a "null pointer constant", not a "null pointer". All pointers, including null pointers are have pointer type. Null pointer constants are integral constants.
MSalters
2009-03-13 09:19:00
A:
What is wrong with calling f(0) is the resolution is ambiguous. Both of your overloaded functions take a pointer which in this case can only be resolved via cast.
f((int*)0)
Depending on what you're trying to do here there are other options that are not ambiguous.
Aaron Saarela
2009-03-13 00:54:33