Various non standard functions are included in the header wchar.h for legacy source code and compatibility with operating system frameworks and application programming interfaces.

• For the function wcsdup see "_wcsdup," for a full description.
• For the function wcsicmp see "_wcsicmp," for a full description.
• For the function wcslwr see "_wcslwr," for a full description.
• For the function wcsincmp see "_wcsnicmp," for a full description.
• For the function wcsnset see "_wcsnset," for a full description.
• For the function wcsrev see "_wcsrev," for a full description.
• For the function wcsset see "_wcsset," for a full description.
• For the function wcspnp see "_wcsspnp," for a full description.
• For the function wcsupr see "_wcsupr," for a full description.
• For the function wtoi see "_wtoi," for a full description.