Re: constness and inheritance

From:

James Kanze <james.kanze@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Fri, 27 Jul 2007 00:57:34 -0700

Message-ID:

<1185523054.411247.179590@k79g2000hse.googlegroups.com>

On Jul 26, 8:05 pm, snd...@gmail.com wrote:

struct A {
  virtual int foo(const int bar);
};

int A::foo(const int bar)
{
  return 0;}

struct B : public A {
  int foo(int bar);};

int B::foo(int bar)
{
  return 1;
}

int
main()
{
        A *p = new B;
        const int baz=-1;
        int r = p->foo(baz);
        return 0;
}

here B::foo is called (tried with g++3.2.3)

Correct. Top level const in a function argument is ignored in
function types.

i wonder if it's a problem for non elementary types in parameters
since derived function can modify the baz argument with impunity
contrary to the expectations of the caller.

What expectations of the caller? All the caller can expect is
never to see the parameter. It's call by copy, remember.

--
James Kanze (GABI Software) email:james.kanze@gmail.com
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