STL string conversion between wstring and string

Question

I am wondering is this adequate enough to use in a production codebase?

std::wstring s2w(const std::string& s)
{
    std::wstring ws;
    ws.assign(s.begin(), s.end());
    return ws;
}

std::string w2s(const std::wstring& w)
{
    std::string s;
    s.assign(w.begin(), w.end());
    return s;
}

AFAIK, no, it isn't adequate, because it doesn't do any conversion (only narrowing). You'll have to do a real conversion between the narrow string encoding and the wide string encoding. For example, using `codecvt`, in C++11 probably combined with `wstring_convert`. — dyp, Aug 08 '13 at 12:35
Similar question: http://stackoverflow.com/questions/7141260/compare-stdwstring-and-stdstring/7159944 — dyp, Aug 08 '13 at 12:40

score 0 · Accepted Answer · answered Aug 08 '13 at 16:29

No, this is not sufficient.

Consider a wstring that contains the following characters (numeric values used for clarity) { 0x41, 0x1243, 0x62 } (That's 'A', followed by ETHIOPIC SYLLABLE QAA, followed by 'b' if you're using Unicode).

Converting to a string using your routine would result in a sequence containing { 0x41, 0x43, 0x42 }, or 'ACb'. Probably not what you expected - or wanted.

As DyP said - you're not doing any conversion, only narrowing.

STL string conversion between wstring and string

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