Re: Extending std::iota function

From:
red floyd <redfloyd@gmail.com>
Newsgroups:
comp.lang.c++.moderated
Date:
Tue, 5 Jul 2011 13:51:51 CST
Message-ID:
<17ba24bb-7dd9-4d86-81c3-33a6a83f46c6@u2g2000yqb.googlegroups.com>
On Jul 4, 6:33 pm, Ricky65 <ricky...@hotmail.com> wrote:

In C++0x the iota function has been added which I find very useful for
testing. However, I find the ability to only increment by 1 to be very
limiting. Sometimes we don't want to fill a container or array with
consecutive integers, we want to control the increment. Consequently,
I feel it would be useful to provide an overload for iota with this
functionality. For example:

//version of iota where user can specify the increment
template <typename Iter, typename Initial_Value, typename Step>
void iota(Iter _First, Iter _Last, Initial_Value value, Step step)
{
        for (; _First != _Last; ++_First, value += step)
                *_First = value;

}


1. Identifiers with a leading underscore followed by an uppercase
     are reserved to the implementation.
2. I don't believe iterators are required to implement +=.

The function should probably read:

//version of iota where user can specify the increment
template <typename Iter, typename Initial_Value, typename Step>
void iota(Iter first, Iter fast, Initial_Value value, Step step)
{
   for (; first != last; ++first, std::advance(value,step))
     *first = value;

}

for (; _First != _Last

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