Re: Isn't this a polymorphic call?

From:
Arindam <arindam.mukerjee@gmail.com>
Newsgroups:
comp.lang.c++
Date:
Thu, 29 May 2008 01:27:41 -0700 (PDT)
Message-ID:
<7b40801e-4734-4eae-a185-b42995169169@p25g2000pri.googlegroups.com>
On May 29, 5:15 am, "A. Bolmarcich" <agge...@earl-grey.cloud9.net>
wrote:

On 2008-05-28, Arindam <arindam.muker...@gmail.com> wrote:

On May 29, 2:14 am, Victor Bazarov <v.Abaza...@comAcast.net> wrote:

Arindam wrote:

#include <cstdio>

struct Test {
void bar() {
foo();
}
private:
virtual void foo() {
printf("Test\n");
}
};

struct Test2 : public Test {
void foo() {
printf("Test2\n");
}
};

int main(int argc, char* argv[])
{
Test2 v;
v.bar();
}


It is not polymorphic according to the inventor of C++, who wrote in
"The C++ Programming Language (Third Edition)":

"To get polymorphic behavior in C++, the member functions called must
be virtual and objects must be manipulated through pointers or
references. When manipulating an object directly (rather than through
a pointer or reference), its exact type is known by the compiler so
that run-time polymorphism is not needed."- Hide quoted text -


As Victor Bazarov suggested, removing the "virtual" keyword is a crisp
test. If you remove it, you will see "Test" being printed instead of
Test2.

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