How to Efficiently Convert `wstring` to `string` in C ?

Converting wstring to string

Problem:
How to effectively convert a wstring to a string in C ?

Context:
In C , wstring and string represent wide character and narrow character strings, respectively. Converting between these two types can be necessary in various scenarios.

Original Attempt:

#include <string>
#include <iostream>

int main() {
    std::wstring ws = L"Hello";
    std::string s(ws.begin(), ws.end());
    std::cout << "std::string =     " << s << std::endl;
    std::wcout << "std::wstring =    " << ws << std::endl;
}

Issue:
The provided example only outputs the initial wstring value, not the string conversion.

Solution using std::wstring_convert:
C 11 introduced std::wstring_convert, which simplifies the conversion process:

#include <locale>
#include <codecvt>

int main() {
    std::wstring ws = L"Hello";

    // Setup converter
    using convert_type = std::codecvt_utf8<wchar_t>;
    std::wstring_convert<convert_type, wchar_t> converter;

    // Convert wstring to string
    std::string s = converter.to_bytes(ws);

    std::cout << "std::string =     " << s << std::endl;
    std::wcout << "std::wstring =    " << ws << std::endl;
}

One-liner Solution:

std::wstring str = std::wstring_convert<std::codecvt_utf8<wchar_t>>().from_bytes("some string");

Wrapper Function Solution:

std::wstring s2ws(const std::string& str) {
    using convert_typeX = std::codecvt_utf8<wchar_t>;
    std::wstring_convert<convert_typeX, wchar_t> converterX;

    return converterX.from_bytes(str);
}

std::string ws2s(const std::wstring& wstr) {
    using convert_typeX = std::codecvt_utf8<wchar_t>;
    std::wstring_convert<convert_typeX, wchar_t> converterX;

    return converterX.to_bytes(wstr);
}

The above is the detailed content of How to Efficiently Convert `wstring` to `string` in C ?. For more information, please follow other related articles on the PHP Chinese website!