Re: Why can't a pure virtual function have an inline definition?

red floyd <>
Thu, 16 Sep 2010 12:03:47 CST
On Sep 15, 9:27 am, Frank Buss <> wrote:

armen.tsirunyan wrote:

It is clearly stated in the current C++ International Standard (2003)
that no virtual function declaration shall contain both a pure
specifier and a definition. I wonder what is the reason of prohibiting
this? I mean, the feature is obviously trivial to implement, it is
more uniform and, well, quite useful. So what considerations am I
missing? Thank you.

This is the same as in the ISO IEC 14882-1999, see chapter 10.4.2, and it
makes sense, because the idea of a "pure virtual" function is, that there
is no definition, so why do you think it would be useful? Providing a
defintion for a virtual function might be useful, but I don't see how it
would make sense for pure virtual functions.

Pure virtual destructors are allowed, yet must have definitions:

struct base {
    virtual ~base() = 0;

base::~base() { }

struct derived : public base {

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