UCS2 easier to use in Visual C++, than UTF encoding. What languages I can not support in UCS2 encoding?
Nothing you're likely to care about or, more to the point, have fonts for. UCS2 gives you the Basic Multilingual Plane; you can find overviews of the assigned planes on the Unicode site
- 0 - Basic Multilingual Plane
- 1 - Supplementary Multilingual Plane (ancient symbols, Klingon, etc.)
- 2 - Supplementary Ideagraphic Plane (CJK unified ideographs extensions)
- 3 - Tertiary Ideographic Plane (ancient Chinese characters)
- 14 - Supplementary Special-Purpose Plane (tag characters and variations - ?)
Of course if you really have UTF-16 support then you can access all of these anyway but if you're asking if you can ignore those then, in practice, probably yes.
The Unicode.org website includes an index of code blocks in code order from which you can see that as of Unicode 6.0, plane 1 includes:
- Linear B Syllabary
- Linear B Ideograms
- Aegean Numbers
- Old Italic
- Gothic
- Ugaritic
- Deseret
- Shavian
- Osmanya
- Cypriot Syllabary
- Byzantine Musical Symbols
- Musical Symbols
- Tai Xuan Jing Symbols
- Mathematical Alphanumeric Symbols
and plane 2 includes:
- CJK Unified Ideographs Extension B
- CJK Compatibility Ideographs Supplement
- Tags
- Variation Selectors Supplement
来源：https://stackoverflow.com/questions/4267318/ucs2-vs-utf-what-languages-can-not-be-displayed-in-the-ucs2-encoding