@node unitypes.h
@chapter Elementary types @code{<unitypes.h>}

The include file @code{<unitypes.h>} provides the following basic types.

@deftp Type uint8_t
@deftpx Type uint16_t
@deftpx Type uint32_t
These are the storage units of UTF-8/16/32 strings, respectively.  The definitions are
taken from @code{<stdint.h>}, on platforms where this include file is present.
@end deftp

@deftp Type ucs4_t
This type represents a single Unicode character, outside of an UTF-32 string.
@end deftp

The types @code{ucs4_t} and @code{uint32_t} happen to be identical.  They differ
in use and intent, however:
@itemize @bullet
@item
Use @code{uint32_t *} to designate an UTF-32 string.  Use @code{ucs4_t} to
designate a single Unicode character, outside of an UTF-32 string.
@item
Conversions functions that take an UTF-32 string as input will usually perform
a range-check on the @code{uint32_t} values.  Whereas functions that are
declared to take @code{ucs4_t} arguments will not perform such a range-check.
@end itemize