Re: Just curious...

From:

ctgqumgf@sharklasers.com

Newsgroups:

comp.lang.c++

Date:

Sat, 5 Jan 2013 01:57:08 -0800 (PST)

Message-ID:

<39cb5544-ba1b-43fe-acb3-420840fd4de3@googlegroups.com>

Am Samstag, 5. Januar 2013 09:33:56 UTC+1 schrieb Giuliano Bertoletti:

Hello, is it correct that the compiler does not issue an error on the fol=

lowing code? =====================
= class Shape { public: void myfunction(); }; class Polygon : public Shap=
e { public: // does not define myfunction }; class Hexagon : public Polygon=
{ public: void myfunction() { Polygon::myfunction(); // why does it compil=
e? } }; ===================== I m=
ean, what is the benefit of implicitly calling Shape::myfunction and not is=
suing an error when I'm explicitly asking to call a non existing Polygon::m=
yfunction? Giulio.

Because that's exactly what public inheritance is for! A method defines
a certain functionality. Inheriting and NOT overriding a method means
the drived class has (wants to have) the same behaviour as the base class.
Some people call this phenomenon "reuse". A good starting point is
http://en.wikipedia.org/wiki/Inheritance_(object-oriented_programming)