c++ Lithuanian language, how to get more than ascii - c++

Question

I am trying to use Lithuanian in my c++ application, but every try is unsuccesfull.
Multi-byte character set is used. I have tryed everything i have tought of, i am new in c++. Never ever tryed to do something in Lithuanian.
Tryed every setlocale(LC_ALL, "en_US.utf8"); setlocale(LC_ALL, "Lithuanian");...
Researched for 2 hours and didnt found proper examples, solution.
I do have a average sized project which needs Lithuanian translation from database and it cant understand most of "ĄČĘĖĮŠŲŪąčęėįšųū".
Compiler - "Visual studio 2013"
Database - sqlite3.
I cant get simple strings to work(defined myself), and output as Lithuanian to win32 application, even.

Answer 1

In Windows use wide character strings (1UTF-16 encoding, wchar_t type) for internal text handling, and preferably UTF-8 for external text files and networking.
Note that Visual C++ will translate narrow text literals from the source encoding to Windows ANSI, which is a platform-dependent usually single-byte encoding (you can check which one via the GetACP API function), i.e., Visual C++ has the platform-specific Windows ANSI as its narrow C++ execution character set.
But also do note that for an app restricted to non-Windows platforms, i.e. Unix-land, it makes practical sense to do everything in UTF-8, based on char type.
For the database communication you may need to translate to and from the program's internal text representation.
This depends on what the database interface requires, which is not stated.
Example for console output in Windows:
#include <iostream>
#include <fcntl.h>
#include <io.h>
auto main() -> int
{
_setmode( _fileno( stdout ), _O_WTEXT );
using namespace std;
wcout << L"ĄČĘĖĮŠŲŪąčęėįšųū" << endl;
}
To make this compile by default with g++, the source code encoding needs to be UTF-8. Then, to make it produce correct results with Visual C++ the source code encoding needs to be UTF-8 with BOM, which happily is also accepted by modern versions of g++. For otherwise the Visual C++ compiler will assume the Windows ANSI encoding and produce an incorrect UTF-16 string.
Not coincidentally this is the default meaning of UTF-8 in Windows, e.g. in the Notepad editor, namely UTF-8 with BOM.
But note that while in Windows the problem is that the main system compiler requires a BOM for UTF-8, in Unix-land the problem is the opposite, that many old tools can't handle the BOM (for example, even MinGW g++ 4.9.1 isn't yet entirely up to speed: it sometimes includes the BOM bytes, then incorrectly interpreted, in error messages).
1) On other platforms wide character text can be encoded in other ways, e.g. with UTF-32. In fact the Windows convention is in direct conflict with the C and C++ standards which require that a single wchar_t should be able to encode any character in the extended character set. However, this requirement was, AFAIK, imposed after Windows adopted UTF-16, so the fault probably lies with the politics of the C and C++ standardization process, not yet another Microsoft'ism.

Answer 2

Complexity of internationalisation
There are several related but distinct topics that can cause mismatches between them, making try and error approach very tedious:
type used for storing strings and chars: windows iuses wchar_t by default, but for most APIs you have also char equivalents functions
character set encoding this defines how the chars stored in the type are to be understood. For exemple unicode (UTF8, UTF16, UTF32), 7 bits ascii, 8 bit ansii. In windows, by default it is UTF16 for wchar_t and ansi/windows for char
locale defines, among other things, the character set asumptions, when processing strings. This permit to use language independent functions like isalpha(i, loc), islower(i, loc), ispunct(i, loc) to find out if a given character is alphanumeric, a lower case alphabetic, or a punctuation, for example to bereak down a user text into words. C++ offers here portable functions.
output codepage or font used to show a character to the user. This assumes that the font used shows the characters using the same character set used in the code internals.
source code encoding. For example your editor could assume an ansi encoding, with windows 1252 character set.
Most typical errors
The problem n°1 is Win32 console output, as unicode is not well supported by the console. But this is not your problem here.
Another cause of mismatch is the encoding of your text editor. It might not be unicode, but use a windows code page. In this case, you type "Č", the deditor displays it as such, but editor might use windows 1257 encoding for lithuanian and store 0xC8 in the file. If you then display this literal with a windows unicode function, it will interpret 0xC8 as "latin E grave accent" and print something else, as the right unicode encoding for "Č" is 0x010C !
I can be even worse: the compiler may have its own assumption about character set encoding used and convert your litterals into unicode using false assumptions (it happened to me when I used some exotic code generation switch).
How to do ?
To figure out what goes wront, proceed by elimination:
First, for plain windows, use the native unicode setting. Ok it's UTF16 and wchar_t instead of UTF8 and as thus comes with some drawbacks, but it's native and well supported.
Then use explict unicode coding in litterals, for example TEXT("\u010C") instead of TEXT("Č"). This avoids editor and compiler mismatch.
If it's still not the right character, make sure that your font FULLY supports unicode. The default system font for instance doesn't while most other do. You can easily check with the windows font pannel (WindowKey+R fonts then click on "search char") to display the character table of your font.
Set fonts explicitely in your code
For example, a very tiny experiment :
...
case WM_PAINT:
{
hdc = BeginPaint(hWnd, &ps);
auto hf = CreateFont(24, 0, 0, 0, 0, TRUE, 0, 0, 0, 0, 0, 0, 0, L"Times New Roman");
auto hfOld = SelectObject(hdc, hf); // if you comment this out, € and Č won't display
TextOut(hdc, 50, 50, L"Test with éç € \u010C special chars", 30);
SelectObject(hdc, hfOld);
DeleteObject(hf);
EndPaint(hWnd, &ps);
break;
}