What are the Pitfalls of C \'s `wchar_t` and `wstrings`, and What Better Alternatives Exist?

What's "Wrong" with C wchar_t and wstrings? What are Some Alternatives to Wide Characters?

Understanding wchar_t

wchar_t in C is a data type intended to represent wide characters that encompass all characters used in different locales. However, its definition does not ensure that it can represent all characters from all supported locales simultaneously.

Limitations of wchar_t and wstrings

The main misconception surrounding wchar_t is its use as a common text representation that allows simple text processing algorithms. However, Unicode breaks the assumption of a one-to-one mapping between characters and codepoints, rendering wchar_t unsuitable for this purpose.

Additionally, wchar_t's encoding may vary between locales, making inter-locale conversions unreliable, especially when Windows is involved. Windows uses UTF-16 for wchar_t, but it does not define __STDC_ISO_10646__, which is required for wchar_t values to represent Unicode codepoints in the same manner across all locales.

Alternatives to Wide Characters

UTF-8 Encoded C Strings: Recommended for platform-independent code, even on platforms that do not natively support UTF-8. It offers a consistent text representation, language support, standard library support, and allows for simple text handling, although not as straightforward as with ASCII.

Cross-Platform Representation (e.g., UTF-16 Arrays): Used by some software, it involves creating a platform-agnostic representation like UTF-16 arrays and providing library support for manipulation and storage.

C 11's char16_t and `char32_t:** Introduced in C 11, these improved wide character types can potentially represent UTF-16 and UTF-32, respectively, and come with enhanced UTF-8 support, making them a viable option for internationalized code.

Alternatives to Avoid

TCHAR: A type used for migrating legacy Windows programs, it is not portable and lacks specificity, making it both unsuitable for cross-platform use and unnecessary since migration to wchar_t is discouraged.

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