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    <blockquote> <p>What if instead two wstring's (as I have now) I want to have one wstring and one string member variable in my class? (I think in such case my code won't work?).</p> </blockquote> <p>There are an inserter defined for <code>char *</code> for any <code>basic_ostream</code> (<code>ostream</code> and <code>wostream</code>), so you can use the result of <code>c_str()</code> member function call for the <code>string</code> member. For example, if the <code>string</code> member is <code>other_data_</code>:</p> <pre><code> return os &lt;&lt; p.price_ &lt;&lt; endl &lt;&lt; p.product_index_ &lt;&lt; endl &lt;&lt; p.product_name_ &lt;&lt; endl &lt;&lt; p.other_data_.c_str() &lt;&lt; endl; </code></pre> <p>The extractor case is more complex, since you'll have to read as <code>wstring</code> and the convert to <code>string</code>. The most simple way to do this is just reading as <code>wstring</code> and then narrowing each character:</p> <pre><code>wstring temp; getline(is, temp); p.other_data_ = string(temp.begin(), temp.end()); </code></pre> <p>I'm not using locales in this sample, just converting a sequence of bytes (8 bits) to a sequence of words (16 bits) for output and the opposite (truncating values) for input. That is OK if you are using ASCII chars, or using single-byte chars and you don't require an specific format (as Unicode) for output.</p> <p>Otherwise, you will need handle with <code>locale</code>s. locale gives cultural contextual information to interpret the string (remember that is just a sequence of bytes, not characters in the sense of letters or symbols; the map between the bytes and what symbol represents is defined by the <code>locale</code>). <code>locale</code> is not an very easy to use concept (human culture isn't too). As you suggest yourself, it would be better make first some investigation about how it works.</p> <p>Anyway, the idea is:</p> <ol> <li>Identify the charset used in string and the charset used in file (Unicode or utf-16).</li> <li>Convert the <code>string</code>s from original charset to Unicode using <code>locale</code> for output.</li> <li>Convert the <code>wstring</code>s read from file (in Unicode) to <code>string</code>s using <code>locale</code>.</li> </ol> <blockquote> <p>Finally, below, in main, when I initialize s2.product_name_= L"megatex"; if instead of megatex I write something in Russian say (e.g., <code>s2.product_name_= L"логин"</code>), the code doesn't work anymore as intended.</p> </blockquote> <p>When you define an array of <code>wchar_t</code> using <code>L""</code>, you'are not really specifying the string is Unicode, just that the array is of chars, not wchar_t. I suppose the intended working is <code>s2.product_name_</code> store the name in Unicode format, but the compiler will take every <code>char</code> in that string (as without <code>L</code>) and convert to <code>wchar_t</code> just padding with zeros the most significant byte. Unicode is not good supported in the C++ standard until C++11 (and is still not really too supported). It works just for ASCII characters because they have the same codification in Unicode (or UTF-8).</p> <p>For using the Unicode characters in a static string, you can use escape characters: <code>\uXXXX</code>. Doing that for every not-English character is not very comfortable, I know. You can found a list of Unicode characters in multiple sites in the web. For example, in the Wikipedia: <a href="http://en.wikipedia.org/wiki/List_of_Unicode_characters" rel="nofollow">http://en.wikipedia.org/wiki/List_of_Unicode_characters</a>.</p>
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    1. POWriting class object to file using streams
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    1. COHonestly, I didn't get much of what you meant. Could you maybe explain that in a more easy to understand way? Thanks.
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    2. COWhat part? first, second or both?
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    3. COAdded samples trying to do easier
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