C language features

To give even more flexibility to the programmer in an Asian environment, ANSI C provides wide character constants and wide string literals. These have the same form as their non-wide versions except that they are immediately prefixed by the letter L:

´x´	regular character constant
´¥´	regular character constant
L´x´	wide character constant
L´¥´	wide character constant
"abc¥xyz"	regular string literal
L"abc¥xyz"	wide string literal

Notice that multibyte characters are valid in both the regular and wide versions. The sequence of bytes necessary to produce the ideogram ¥ is encoding-specific, but if it consists of more than one byte, the value of the character constant '¥' is implementation defined, just as the value of 'ab' is implementation defined. A regular string literal contains exactly the bytes (except for escape sequences) specified between the quotes, including the bytes of each specified multibyte character.

When the compilation system encounters a wide character constant or wide string literal, each multibyte character is converted (as if by calling the mbtowc function) into a wide character. Thus the type of L'¥' is wchar_t and the type of L"abc¥xyz" is array of wchar_t with length eight. (Just as with regular string literals, each wide string literal has an extra zero-valued element appended, but in these cases it is a wchar_t with value zero.)

Just as regular string literals can be used as a short-hand method for character array initialization, wide string literals can be used to initialize wchar_t arrays:

   wchar_t *wp = L"a¥z";
   wchar_t x[] = L"a¥z";
   wchar_t y[] = {L'a', L'¥', L'z', 0};
   wchar_t z[] = {'a', L'¥', 'z', '\0'};

Finally, adjacent wide string literals will be concatenated, just as with regular string literals. However, adjacent regular and wide string literals produce undefined behavior. A compiler is not even required to complain if it does not accept such concatenations.