Article View: comp.std.c++
Article #3450Returning void
From: Paul D. DeRocco
Date: Sun, 18 Feb 1996 02:14
Date: Sun, 18 Feb 1996 02:14
34 lines
1813 bytes
1813 bytes
The C++ standard doesn't allow a return statement with an expression to
be used in a function whose return type is void.
I suggest that it should be legal to return a void expression from a
function whose type is void. Why? It can be useful in templates.
Consider the following:
template <class T, class R> class Functor {
public:
R& operator()() { return (obj.*mem)(); }
Functor(T& o, R& (T::*m)()): obj(o), mem(m) {}
private:
T& obj;
R& (T::*mem)();
}
This defines a functor containing a pointer to an object to be operated
on, and a pointer to a member function defined for that object. It
should work for any member function that takes no arguments and returns
a result. Unfortunately, it won't work for a member function that
returns void. If return were modified as described above, this function
template would work for member functions that return void as well.
--
Ciao,
Paul D. DeRocco
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Path: arc1-ca.pugleaf.net!engnews1.Eng.Sun.COM!taumet!clamage From: "Paul D. DeRocco" <pderocco@ix.netcom.com> Newsgroups: comp.std.c++ Subject: Returning void Date: 18 Feb 1996 02:14:49 GMT Organization: ? Approved: clamage@eng.sun.com (comp.std.c++) Message-ID: <3125C4A3.5C00@ix.netcom.com> NNTP-Posting-Host: taumet.eng.sun.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 2.0b6a (Win95; I) Content-Length: 957 Originator: clamage@taumet