Re: polymorphic method override
On 15.05.2010 23:36, * stf:
Why does this code not compile?
#include<iostream>
using namespace std;
class A {
public:
virtual void myMethod(const string& s) const;
};
class B : public A {
public:
virtual void myMethod(int x) const;
};
void A::myMethod(const string& s) const {
cerr<< "(A) myMethod: s is: "<< s<< endl;
}
void B::myMethod(int x) const {
cerr<< "(B) myMethod: x = "<< x<< endl;
}
int main() {
std::string s("my string one");
B b;
b.myMethod(s);
return 0;
}
The error is:
$ g++ -Wall ./test-5.cpp -o test-5.out ./test-5.cpp: In function
???int main()???:
./test-5.cpp:25: error: no matching function for call to
???B::myMethod(std::string&)???
./test-5.cpp:18: note: candidates are: virtual void B::myMethod(int)
const
This is a FAQ.
It's often a good idea to check the FAQ (or a textbook) before posting.
See http://www.parashift.com/c++-faq-lite/strange-inheritance.html#faq-23.9
Cheers & hth.,
- Alf
--
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