string.hpp

#pragma once
 
#include <string>
#include <sstream>
#include <string_view>
#include <iterator>
#include <vector>
#include <stdexcept>
 
#if defined _WIN32 || defined WINCE
#define LITEFX_CODECVT_USE_WIN32
#include <Windows.h>
#else
// Continue using std::codecvt for now, since other platforms than Win32 are currently unsupported anyway.
#include <codecvt>
#endif
 
namespace LiteFX {
    using String = std::string;
    using WString = std::wstring;
    using StringView = std::string_view;
    using WStringView = std::wstring_view;
 
    // Based on: https://stackoverflow.com/a/5289170/1254352
    template <typename TStrings, typename Value = typename TStrings::value_type>
    String Join(const TStrings& elements, const String& delimiter = "") 
    {
        std::ostringstream stream;
 
        auto beg = std::begin(elements);
        auto end = std::end(elements);
 
        if (beg != end) 
        {
            std::copy(beg, std::prev(end), std::ostream_iterator<Value>(stream, delimiter.c_str()));
            beg = std::prev(end);
        }
 
        if (beg != end)
            stream << *beg;
 
        return stream.str();
    }
 
    inline WString Widen(StringView utf8)
    {
#if defined LITEFX_CODECVT_USE_WIN32
        if (utf8.empty())
            return L"";
 
        const auto size = ::MultiByteToWideChar(CP_UTF8, 0, utf8.data(), static_cast<int>(utf8.size()), nullptr, 0);
 
        if (size <= 0)
            throw std::runtime_error("Unable to convert string to UTF-16: " + std::to_string(size));
 
        WString result(size, 0);
        ::MultiByteToWideChar(CP_UTF8, 0, utf8.data(), static_cast<int>(utf8.size()), result.data(), size);
 
        return result;
#else
        std::wstring_convert<std::codecvt_utf8_utf16<WCHAR>> conv;
        return conv.from_bytes(utf8);
#endif
    }
 
    inline String Narrow(WStringView utf16)
    {
#if defined LITEFX_CODECVT_USE_WIN32
        if (utf16.empty())
            return "";
 
        const auto size = ::WideCharToMultiByte(CP_UTF8, 0, utf16.data(), static_cast<int>(utf16.size()), nullptr, 0, nullptr, nullptr);
 
        if (size <= 0)
            throw std::runtime_error("Unable to convert string to UTF-8: " + std::to_string(size));
 
        String result(size, 0);
        ::WideCharToMultiByte(CP_UTF8, 0, utf16.data(), static_cast<int>(utf16.size()), result.data(), size, nullptr, nullptr);
 
        return result;
#else
        std::wstring_convert<std::codecvt_utf8_utf16<WCHAR>> conv;
        return conv.to_bytes(utf16);
#endif
    }
}
 
#undef LITEFX_CODECVT_USE_WIN32