The R installer can now be optionally built to support a single

architecture (only 64-bit or only 32-bit).

The default C++ standard has been changed to C++14 where

(as before) C++11 is used if available otherwise C++ is not

Packages which specify C++11 will still be installed using C++11.

C++14 compilers may give deprecation warnings, most often for

or modernize the code and if needed specify C++14.  The latter has

This provides a valuable check on code consistency.  It does work

Rtools40, but that does not detect everything

The default personal library directory on builds with

(and hence the packages) were built for,

build of R is run under Rosetta emulation on

statements, which were possibly intended as

Meyer). This check can be activated via the new environment

previous builds from the top-level package directory.

and has a documented value.  For packages

, there is a reference to the code given

as they cannot be represented by valid UTF-8.

Where such escapes are used for outputting non-printable

(including unassigned) characters, 6 hex digits are used (rather

than 8 with leading zeros).  For clarity, braces are used, for

The parser now looks for non-ASCII spaces on Solaris (as

There are warnings (including from the parser) on the use of

unpaired surrogate Unicode points such as

and those using regular expressions have more

support for inputs with a marked Latin-1 encoding.

The character-classification functions used (by default) to

AIX have been updated to Unicode 13.0.0.

The character-width tables have been updated to include new

assignments in Unicode 13.0.0.  This included treating all control

The code for evaluating default (extended) regular

expressions now uses the same character-classification functions

(previously they differed on Windows, macOS and

There is a build-time option to replace the system's

work with Unicode characters beyond the Basic Multilingual Plane

where not supported by system functions (e.g. on Solaris where it

R is more careful when truncating UTF-8 and other multi-byte