New in the 1.9.x rtl (not yet in the docs)
From Free Pascal wiki
The following stuff is new in 1.9.x and is not yet in the docs:
- A lot of integer types are changed to SizeInt/SizeUInt to have common declarations for 32 and 64 Bit targets.
The following routines are new in the 1.9.x rtl and aren't yet documented:
function UnicodeToUtf8(Dest: PChar; Source: PWideChar; MaxBytes: SizeInt): SizeInt; function UnicodeToUtf8(Dest: PChar; MaxDestBytes: SizeUInt; Source: PWideChar; SourceChars: SizeUInt): SizeUInt; function Utf8ToUnicode(Dest: PWideChar; Source: PChar; MaxChars: SizeInt): SizeInt; function Utf8ToUnicode(Dest: PWideChar; MaxDestChars: SizeUInt; Source: PChar; SourceBytes: SizeUInt): SizeUInt;
See also Language related articles for compiler stuff not yet documented.
UPD: Now it documented in UTF-8 page.