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

[Whit Armstrong]

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


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