Convert ASCII string to Unicode? Windows, pure C

Question

I've found answers to this question for many programming languages, except for C, using the Windows API. No C++ answers please. Consider the following:

#include <windows.h>
char *string = "The quick brown fox jumps over the lazy dog";
WCHAR unistring[strlen(string)+1];

What function can I use to fill unistring with the characters from string?

Answer 1

MultiByteToWideChar:

#include <windows.h>
char *string = "The quick brown fox jumps over the lazy dog";
size_t len = strlen(string);
WCHAR unistring[len + 1];
int result = MultiByteToWideChar(CP_OEMCP, 0, string, -1, unistring, len + 1);

Answer 2

If you are really serious about Unicode, you should refer to International Components for Unicode, which is a cross-platform solution for handling Unicode conversions and storage in either C or C++.

Your WCHAR, for example, is not Unicode to begin with, because Microsoft somewhat prematurely defined wchar_t to be 16bit (UCS-2), and got stuck in backward compatibility hell when Unicode became 32bit: UCS-2 is almost, but not quite identical to UTF-16, the latter being in fact a multibyte encoding just like UTF-8. "Wide" format in Unicode means 32 bit (UTF-32), and even then you don't have a 1:1 relationship between code points (i.e. 32bit-values) and abstract characters (i.e. a printable glyph).

Gratuituous, losely related list of links:

• The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!) by Joel Spolsky
• The UTF-8 Everywhere Manifesto
• Commonly confused characters by Greg Baker