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    copied!<p>If what you're really doing is manipulating a CSV file itself, Nelson's answer makes sense. However, my suspicion is that the CSV is simply an artifact of the problem you're solving. In C++, that probably means you have something like this as your data model:</p> <pre><code>struct Customer { int id; std::string first_name; std::string last_name; struct { std::string street; std::string unit; } address; char state[2]; int zip; }; </code></pre> <p>Thus, when you're working with a collection of data, it makes sense to have <code>std::vector&lt;Customer&gt;</code> or <code>std::set&lt;Customer&gt;</code>.</p> <p>With that in mind, think of your CSV handling as two operations:</p> <pre><code>// if you wanted to go nuts, you could use a forward iterator concept for both of these class CSVReader { public: CSVReader(const std::string &amp;inputFile); bool hasNextLine(); void readNextLine(std::vector&lt;std::string&gt; &amp;fields); private: /* secrets */ }; class CSVWriter { public: CSVWriter(const std::string &amp;outputFile); void writeNextLine(const std::vector&lt;std::string&gt; &amp;fields); private: /* more secrets */ }; void readCustomers(CSVReader &amp;reader, std::vector&lt;Customer&gt; &amp;customers); void writeCustomers(CSVWriter &amp;writer, const std::vector&lt;Customer&gt; &amp;customers); </code></pre> <p>Read and write a single row at a time, rather than keeping a complete in-memory representation of the file itself. There are a few obvious benefits:</p> <ol> <li>Your data is represented in a form that makes sense for your problem (customers), rather than the current solution (CSV files).</li> <li>You can trivially add adapters for other data formats, such as bulk SQL import/export, Excel/OO spreadsheet files, or even an HTML <code>&lt;table&gt;</code> rendering.</li> <li>Your memory footprint is likely to be smaller (depends on relative <code>sizeof(Customer)</code> vs. the number of bytes in a single row).</li> <li><code>CSVReader</code> and <code>CSVWriter</code> can be reused as the basis for an in-memory model (such as Nelson's) without loss of performance or functionality. The converse is not true.</li> </ol>
 

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