add support for 'cpp2b' as well

Author: eddelbuettel

ChangeLog

@@ -3,7 +3,8 @@
 	* DESCRIPTION (Version, Date): Roll minor version
 	* inst/include/Rcpp/config.h: Idem
 
-	* R/Attributes.R: Support C++20 and C++23 via plugins
+	* R/Attributes.R: Support C++20, C++23 and C++2b (for experimental /
+	incomplete support) via new plugins
 
 2022-07-27  Dirk Eddelbuettel  <edd@debian.org>
 

R/Attributes.R

@@ -573,6 +573,11 @@ compileAttributes <- function(pkgdir = ".", verbose = getOption("verbose")) {
     list(env = list(PKG_CXXFLAGS ="-std=c++2a"))
 }
 
+## built-in C++2b plugin for compilers without C++23 support
+.plugins[["cpp2b"]] <- function() {
+    list(env = list(PKG_CXXFLAGS ="-std=c++2b"))
+}
+
 ## built-in OpenMP plugin
 .plugins[["openmp"]] <- function() {
     list(env = list(PKG_CXXFLAGS="-fopenmp",

inst/NEWS.Rd

@@ -15,8 +15,8 @@
     }
     \item Changes in Rcpp Attributes:
     \itemize{
-      \item The C++20 and C+=23 standards are now supported via plugins
-      just like the other C++ standards (Dirk in \ghpr{1228})
+      \item The C++20, C++2b (experimental) and C++23 standards now have
+      plugin support like the other C++ standards (Dirk in \ghpr{1228})
     }
   }
 }