Re: C++ reluctant to overload function

From:

Pete Becker <pete@versatilecoding.com>

Newsgroups:

comp.lang.c++

Date:

Thu, 14 Oct 2010 09:59:24 -0400

Message-ID:

<2010101409592461253-pete@versatilecodingcom>

On 2010-10-13 15:15:22 -0400, Steve Pope said:

Pete Becker <pete@versatilecoding.com> wrote:

On 2010-10-13 11:59:29 -0400, Steve Pope said:

The whole idea of overloading is to provide the programmer with
a form of polymorphism. e.g. I have a math library function

double sin(double x)

And I want to overloaded it with a vector version

vector<double> sin(vector<double> x)

Because one scope encloses the other I cannot do this without some
sort of workaround.

Did you try this? Add #include <math.h> and it should work just fine.

Or, if you're a namespace purist, use #include <cmath> and put your
function in namespace std like the rest of the math functions.

Either way, there's no "workaround" needed. Just follow the langauge rules.

I notice that with #include <cmath>, in this sort of case g++ requires
neither a "using" statement, nor putting your overloaded function into
std... even when compiled with -pedantic.

This almost seems like a bug.

I haven't looked, but my guess is that <cmath> puts the names in both
the global namespace and namespace std. That's quite common, and the
next revision of the standard will explicitly allow that, since the
current requirement, driven by wishful thinking, is impractical.

--
Pete
Roundhouse Consulting, Ltd. (www.versatilecoding.com) Author of "The
Standard C++ Library Extensions: a Tutorial and Reference
(www.petebecker.com/tr1book)