I wished to use transform with an out iterator equal to one of the input
iterators.  I realised what I want is something more akin to for_each but
with an extra iterator parameter and a necessary binary_op parameter.  Does
anyone agree that this is useful and should be a standard algorithm?


BinaryOperation transform_each(InputIterator1 first1,
    InputIterator1 last1,
    InputIterator2 first2,
    BinaryOperation binary_op);

first1 to last1 elements can be modified via a reference, and theres no need
for construction of a temporary and copy assignment as with transform.  This
is also easier than using for_each with a complex functor.

Fraser.


---
[ comp.std.c++ is moderated.  To submit articles, try just posting with ]
[ your news-reader.  If that fails, use mailto:std-c++@ncar.ucar.edu    ]
[              --- Please see the FAQ before posting. ---               ]
[ FAQ: http://www.jamesd.demon.co.uk/csc/faq.html                       ]

fraser@members.v21.co.uk ("Fraser Ross") wrote in message news:<003601c36ae4$4c556b20$594279d5@frasercomputer>...
> I wished to use transform with an out iterator equal to one of the input
> iterators.  I realised what I want is something more akin to for_each but
> with an extra iterator parameter and a necessary binary_op parameter.  Does
> anyone agree that this is useful and should be a standard algorithm?
>
>
> BinaryOperation transform_each(InputIterator1 first1,
>     InputIterator1 last1,
>     InputIterator2 first2,
>     BinaryOperation binary_op);
>
> first1 to last1 elements can be modified via a reference, and theres no need
> for construction of a temporary and copy assignment as with transform.  This
> is also easier than using for_each with a complex functor.

I wonder if there's a large benefit here, anyone could write it provided
they realized that InputIterator1 would actually have to be a
ForwardIterator (since it's also used for Output).

The only benefit I could see is that a std:: version could use the std::'s
concept check system to verify that binary_op's types are correct, if
the Standard Library has such a framework in place.

Regards,
--
Michiel Salters

---
[ comp.std.c++ is moderated.  To submit articles, try just posting with ]
[ your news-reader.  If that fails, use mailto:std-c++@ncar.ucar.edu    ]
[              --- Please see the FAQ before posting. ---               ]
[ FAQ: http://www.jamesd.demon.co.uk/csc/faq.html                       ]