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POhow to iterate into a smaller container (i.e. stride != 1)
 

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    <p>There is a question that is very similar in spirit <a href="https://stackoverflow.com/questions/2476425/c-stl-stdtransform-with-given-stride">here</a>. Unfortunately that question didn't prompt much response - I thought I would ask a more specific question with the hope that an alternative method can be suggested.</p> <p>I'm writing a binary file into <code>std::cin</code> (with <code>tar --to-command=./myprog</code>). The binary file happens to be a set of floats and I want to put the data into <code>std::vector&lt;float&gt;</code> - ideally the c++ way.</p> <p>I can generate a <code>std::vector&lt;char&gt;</code> very nicely (thanks to <a href="https://stackoverflow.com/questions/5420317/c-reading-and-writing-binary-file/5420568#5420568">this answer</a>)</p> <pre><code>#include &lt;fstream&gt; #include &lt;iostream&gt; #include &lt;iterator&gt; #include &lt;algorithm&gt; #include &lt;vector&gt; int main (int ac, char **av) { std::istream&amp; input = std::cin; std::vector&lt;char&gt; buffer; std::copy( std::istreambuf_iterator&lt;char&gt;(input), std::istreambuf_iterator&lt;char&gt;( ), std::back_inserter(buffer)); // copies all data into buffer } </code></pre> <p>I now want to transform my <code>std::vector&lt;char&gt;</code> into a <code>std::vector&lt;float&gt;</code>, presumably with <code>std::transform</code> and a function that does the conversion (a <code>char[2]</code> to a <code>float</code>, say). I am struggling however, because my <code>std::vector&lt;float&gt;</code> will have half as many elements as <code>std::vector&lt;char&gt;</code>. If I could iterate with a stride of 2 then I think I would be fine, but from the previous question it seems that I cannot do that (at least not elegantly).</p>
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    1. COWhy read in `char`'s? Why not `std::string`'s? It's unclear what you want to be able to input, and what you want to accomplish.
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    2. CO@GMan, I want to finish with a std::vector<float> from a binary file inputted into cin - I can then use a library function to decode the std::vector. If proceeding via stings is easier then thats fine (It wasn't clear to me how to do that with cin).
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    3. CO@Tom: What is the format of the binary file?
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