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copied!<p><code>char</code> is for 8-bit code units, <code>char16_t</code> is for 16-bit code units, and <code>char32_t</code> is for 32-bit code units. Any of these can be used for 'Unicode'; UTF-8 uses 8-bit code units, UTF-16 uses 16-bit code units, and UTF-32 uses 32-bit code units.</p> <hr> <p>The guarantee made for <code>wchar_t</code> was that any character supported in a locale could be converted from <code>char</code> to <code>wchar_t</code>, and whatever representation was used for <code>char</code>, be it multiple bytes, shift codes, what have you, the <code>wchar_t</code> would be a single, distinct value. The purpose of this was that then you could manipulate <code>wchar_t</code> strings just like the simple algorithms used with ASCII.</p> <p>For example, converting ascii to upper case goes like:</p> <pre><code>auto loc = std::locale(""); char s[] = "hello"; for (char &c : s) { c = toupper(c, loc); } </code></pre> <p>But this won't handle converting all characters in UTF-8 to uppercase, or all characters in some other encoding like Shift-JIS. People wanted to be able to internationalize this code like so:</p> <pre><code>auto loc = std::locale(""); wchar_t s[] = L"hello"; for (wchar_t &c : s) { c = toupper(c, loc); } </code></pre> <p>So every <code>wchar_t</code> is a 'character' and if it has an uppercase version then it can be directly converted. Unfortunately this doesn't really work all the time; For example there exist oddities in some languages such as the German letter ß where the uppercase version is actually the two characters SS instead of a single character.</p> <p>So internationalized text handling is intrinsically harder than ASCII and cannot really be simplified in the way the designers of <code>wchar_t</code> intended. As such <code>wchar_t</code> and wide characters in general provide little value.</p> <p>The only reason to use them is that they've been baked into some APIs and platforms. However, I prefer to stick to UTF-8 in my own code even when developing on such platforms, and to just convert at the API boundaries to whatever encoding is required.</p>

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