Unicode in C++

Question

What's the best practice of unicode processing in C++?

Answer 1

Here is a checklist for Windows programming:

• All strings enclosed in _T("my string")
• strlen() etc. functions replaced with _tcslen() etc.
• Use LPTSTR and LPCTSTR instead of char * and const char *
• When starting new projects in Dev Studio, religiously make sure the Unicode option is selected in your project properties.
• For C++ strings, use std::wstring instead of std::string

Answer 2

• Use ICU for dealing with your data (or a similar library)
• In your own data store, make sure everything is stored in the same encoding
• Make sure you are always using your unicode library for mundane tasks like string length, capitalization status, etc. Never use standard library builtins like is_alpha unless that is the definition you want.
• I can't say it enough: _**never iterate over the indices of a string if you care about correctness, always use your unicode library for this.**_

Answer 3

Use IBM's International Components for Unicode

Answer 4

Look at http://stackoverflow.com/questions/11635/case-insensitive-string-comparison-in-c

That question has a link to the Microsoft documentation on Unicode: http://msdn.microsoft.com/en-us/library/cc194799.aspx

If you look on the left-hand navigation side on MSDN next to that article, you should find a lot of information pertaining to Unicode functions. It is part of a chapter on "Encoding Characters" (http://msdn.microsoft.com/en-us/library/cc194786.aspx)

It has the following subsections:

• The Code-Page Model
• Double-Byte Character Sets in Windows
• Unicode
• Compatibility Issues in Mixed Environments
• Unicode Data Conversion
• Migrating Windows-Based Programs to Unicode
• Summary

Answer 5

Our company (and others) use the open source Internation Components for Unicode (ICU) library originally developed by Taligent.

It handles strings, locales, conversions, date/times, collation, transformations, et. al.

Start with the ICU Userguide