I noticed that in this C++09x proposal for concatenating tuples:

    http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2299.html

there is no mention given to the idea of overloading the plus operator
(+) to allow one tuple to be "added" to another (just as std::string
objects can be combined.) Offhand, I would think an overloaded plus
operator would make a lot of sense in this case, but perhaps there are
arguments against the idea. So, I guess my question is: would an
overloaded plus operator be a reasonable way to concatenate two tuple
objects of (possibly) differing types?

Greg

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On 5 Jul., 22:18, Greg Herlihy <gre...@pacbell.net> wrote:
> I noticed that in this C++09x proposal for concatenating tuples:
>
>    http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2299.html
>
> there is no mention given to the idea of overloading the plus operator
> (+) to allow one tuple to be "added" to another (just as std::string
> objects can be combined.) Offhand, I would think an overloaded plus
> operator would make a lot of sense in this case, but perhaps there are
> arguments against the idea. So, I guess my question is: would an
> overloaded plus operator be a reasonable way to concatenate two tuple
> objects of (possibly) differing types?

Although operator+ is probably the most frequent used symbolic
concatenator for strings, several people have argued, that it is not
the most reasonable one, argueing from commutativity of +, which
does not fit well with contatenations. One of the rare exceptions
here is the usage of the asymmetric operator // in Fortran 90
to concatenate strings (which would not be allowed in C++).

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2233.html

has proposed to add operator<< for strings, so what about this?

Personally I don't expect a very frequent usage of the capability
to concatenate tuples - but maybe I have a false impression on that?

Greetings from Bremen,

Daniel Kr   gler


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