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    <p>You should convert the <code>char</code> string to a <code>wchar_t</code> string using <code>mbstowcs</code>, and then compare the resulting strings. Notice that <code>mbstowcs</code> works on <code>char *</code>/<code>wchar *</code>, so you'll probably need to do something like this:</p> <pre><code>std::wstring StringToWstring(const std::string &amp; source) { std::wstring target(source.size()+1, L' '); std::size_t newLength=std::mbstowcs(&amp;target[0], source.c_str(), target.size()); target.resize(newLength); return target; } </code></pre> <p>I'm not entirely sure that that usage of <code>&amp;target[0]</code> is entirely standard-conforming, if someone has a good answer to that please tell me in the comments. Also, there's an implicit assumption that the converted string won't be longer (in number of <code>wchar_t</code>s) than the number of <code>char</code>s of the original string - a logical assumption that still I'm not sure it's covered by the standard.</p> <p>On the other hand, it seems that there's no way to ask to <code>mbstowcs</code> the size of the needed buffer, so either you go this way, or go with (better done and better defined) code from Unicode libraries (be it Windows APIs or libraries like iconv).</p> <p>Still, keep in mind that comparing Unicode strings without using special functions is slippery ground, two equivalent strings may be evaluated different when compared bitwise.</p> <p>Long story short: this should work, and I think it's the maximum you can do with just the standard library, but it's a lot implementation-dependent in how Unicode is handled, and I wouldn't trust it a lot. In general, it's just better to stick with an encoding inside your application and avoid this kind of conversions unless absolutely necessary, and, if you are working with definite encodings, use APIs that are less implementation-dependent.</p>
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    1. POCompare std::wstring and std::string
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    1. CO`wstring` cannot be constructed on a single number, and even if it could, you'd end up with a string of the wrong length. You really have to call `mbstowcs` twice to get the required target length.
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    2. CONote that if the string holds non-English text or UTF-8, this might not work. In windows there's MBTWC, as @Don Reba suggests, but it's obviously not portable, if that matters to the OP.
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    3. CO@eran: `mbstowcs` is entirely encoding agnostic. It merely translates between "the system's multibyte representation" and "the system's wide character". There is no requirement for either of those to be anything you'd recognize. If you want a definite encoding, you have to follow this up with an `iconv()` conversion from WCHAR to your favourite (Unicode?) encoding. Here is a [little rant](http://stackoverflow.com/questions/6300804/wchars-encodings-standards-and-portability) of mine on the subject.
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