[Rcpp-devel] cxxfunction -- extra argument to g++

[Dirk Eddelbuettel]

On 24 January 2012 at 15:36, Whit Armstrong wrote:
| Thanks, Dirk, as always for the quick response.
| 
| It works, but I get an unusual compile error with the most recent
| RcppArmadillo (installed with install.packages this morning).
| 
| require(inline)
| require(Rcpp)
| require(RcppArmadillo)
| cppbugs.plugin <- getPlugin("RcppArmadillo")
| cppbugs.plugin$env$PKG_CXXFLAGS <- "-std=c++0x"
| foo <- cxxfunction(signature(hat="numeric"), body="return
| R_NilValue;",settings=cppbugs.plugin)
| 
| results in:
| 
| Error in compileCode(f, code, language = language, verbose = verbose) :
|   Compilation ERROR, function(s)/method(s) not created! In file
| included from /usr/local/lib/R/site-library/RcppArmadillo/include/armadillo_bits/Mat_meat.hpp:6091:0,
|                  from
| /usr/local/lib/R/site-library/RcppArmadillo/include/armadillo:369,
|                  from
| /usr/local/lib/R/site-library/RcppArmadillo/include/RcppArmadilloForward.h:36,
|                  from
| /usr/local/lib/R/site-library/RcppArmadillo/include/RcppArmadillo.h:25,
|                  from file1724747be803.cpp:3:
| /usr/local/lib/R/site-library/RcppArmadillo/include/RcppArmadillo/Mat_meat.h:
| In function ‘void arma::RcppArmadillo::check()’:
| /usr/local/lib/R/site-library/RcppArmadillo/include/RcppArmadillo/Mat_meat.h:34:5:
| error: expected ‘;’ before ‘}’ token
| make: *** [file1724747be803.o] Error 1
| In addition: Warning message:
| running command '/usr/lib/R/bin/R CMD SHLIB file1724747be803.cpp 2>
| file1724747be803.cpp.err.txt' had status 1


Easy enough:

    inline void check(){
#if !defined(ARMA_USE_CXX11)
	arma_type_check_cxx1998< is_same_type< eT, rcpp_type >::value == false >::apply();
#else
	static_assert( is_same_type< eT, rcpp_type >::value , "error: incorrect or unsupported type" )
#endif
    }

There is indeed a semicolon missing in the released version, but I seem to
have added that in svn commit 3438.  Should get fixed in the next release. Ah
yes, and ChangeLog says that we had this reported on Dec 31 by Teo Guo Ci

2011-12-31  Dirk Eddelbuettel  <edd at debian.org>

	* inst/include/RcppArmadillo/Mat_meat.h: Add missing semicolon in
	code ifdef'ed for C++0x mode, with thanks to Teo Guo Ci


Dirk


| 
| Probably something I've overlooked.
| 
| However, changing the 'cppbugs.plugin <- getPlugin("RcppArmadillo")'
| command to 'cppbugs.plugin <- getPlugin("Rcpp")' allows the example to
| compile.
| 
| Is there a c++0x issue in the latest RcppArmadillo?  I have:
| Version:            0.2.34
| Date:               $Date: 2011-12-12 16:56:37 -0600 (Mon, 12 Dec 2011) $
| 
| Anyway, I'll keep tinkering...
| 
| -Whit
| 
| 
| 
| 
| On Tue, Jan 24, 2012 at 3:18 PM, Dirk Eddelbuettel <edd at debian.org> wrote:
| >
| > On 24 January 2012 at 14:46, Whit Armstrong wrote:
| > | using cxxfunction is there an easy (not using a custom plugin) way to
| > | add -std=c++0x to the g++ call?
| >
| > The best way, I think, is to call a plugin and to modify it.
| >
| > Quick example:
| >
| >
| > R> myplugin <- getPlugin("Rcpp")
| > R> myplugin$env$PKG_CXXFLAGS <- "-std=c++0x"
| > R> f <- cxxfunction(signature(), settings=myplugin, body='
| > +    std::vector<double> x = { 1.0, 2.0, 3.0 };  // fails without -std=c++0x
| > +    return Rcpp::wrap(x);
| > + ')
| > R> f()
| > [1] 1 2 3
| > R>
| >
| >
| > If you don't use the modified settings, it'll blow up as the 'curly init' is
| > a new feature:
| >
| >   filebee52557bd2.cpp:32:44: error: in C++98 ‘x’ must be initialized by constructor, not by ‘{...}’
| >   filebee52557bd2.cpp:32:44: error: could not convert ‘{1.0e+0, 2.0e+0, 3.0e+0}’ from ‘<brace-enclosed initializer list>’ to ‘std::vector<double>’
| >
| > but with the switch it all flies.
| >
| > I think I'll add that to the Rcpp-FAQ now.
| >
| > Note though that here I simply assigned PKG_CXXFLAGS which had been empty as
| > the Rcpp plugin does not set it. Other plugins may, so you one may have
| > append rather than overwrite.
| >
| > Dirk
| >
| > --
| > "Outside of a dog, a book is a man's best friend. Inside of a dog, it is too
| > dark to read." -- Groucho Marx

-- 
"Outside of a dog, a book is a man's best friend. Inside of a dog, it is too
dark to read." -- Groucho Marx