long long warnings in algorithm.h

[nathan-russell]

Per @dcdillon's comment in #501,

The long long warnings are puzzling as all references to long long seem to be wrapped in ifdefs appropriately

in reference to @thirdwing's compiler output,

* checking whether package ‘with.dot’ can be installed ... WARNING
Found the following significant warnings:
/Library/Frameworks/R.framework/Versions/3.2/Resources/library/Rcpp/include/Rcpp/algorithm.h:48:62: warning: 'long long' is a C++11 extension [-Wc++11-long-long] 
/Library/Frameworks/R.framework/Versions/3.2/Resources/library/Rcpp/include/Rcpp/algorithm.h:77:80: warning: 'long long' is a C++11 extension [-Wc++11-long-long]   
/Library/Frameworks/R.framework/Versions/3.2/Resources/library/Rcpp/include/Rcpp/algorithm.h:89:43: warning: 'long long' is a C++11 extension [-Wc++11-long-long] 
/Library/Frameworks/R.framework/Versions/3.2/Resources/library/Rcpp/include/Rcpp/algorithm.h:100:61: warning: 'long long' is a C++11 extension [-Wc++11-long-long] 
/Library/Frameworks/R.framework/Versions/3.2/Resources/library/Rcpp/include/Rcpp/algorithm.h:117:43: warning: 'long long' is a C++11 extension [-Wc++11-long-long]   
/Library/Frameworks/R.framework/Versions/3.2/Resources/library/Rcpp/include/Rcpp/algorithm.h:128:61: warning: 'long long' is a C++11 extension [-Wc++11-long-long] 

I have also been experiencing this with more recent versions of Rcpp (since the addition of algorithm.h). As far as I can tell, this only happens when compiling with clang and passing the -pedantic flag:

devtools::install_github("RcppCore/Rcpp") 

clang++ -I/usr/share/R/include -DNDEBUG -I../inst/include/ \   
-fpic  -g -O2 -fstack-protector --param=ssp-buffer-size=4 \
-Wformat -Wall -pedantic -Werror=format-security -D_FORTIFY_SOURCE=2 \
-g  -c Date.cpp -o Date.o

In file included from Date.cpp:31:
In file included from ../inst/include/Rcpp.h:84:
../inst/include/Rcpp/algorithm.h:48:62: warning: 'long long' is a C++11 extension [-Wc++11-long-long]
    struct ctype_helper< sizeof(CTYPE_LONG_LONG) > { typedef long long type; static const bool value = true; };
                                                             ^
../inst/include/Rcpp/algorithm.h:77:80: warning: 'long long' is a C++11 extension [-Wc++11-long-long]
    struct ctype_helper< sizeof(CTYPE_UNSIGNED_LONG_LONG) > { typedef unsigned long long type; static const bool value = true; };
                                                                               ^
../inst/include/Rcpp/algorithm.h:89:43: warning: 'long long' is a C++11 extension [-Wc++11-long-long]
        static CTYPE_LONG_LONG test(const long long &);
                                          ^
../inst/include/Rcpp/algorithm.h:100:61: warning: 'long long' is a C++11 extension [-Wc++11-long-long]
        static CTYPE_UNSIGNED_LONG_LONG test(const unsigned long long &);
                                                            ^
../inst/include/Rcpp/algorithm.h:117:43: warning: 'long long' is a C++11 extension [-Wc++11-long-long]
        static CTYPE_LONG_LONG test(const long long &);
                                          ^
../inst/include/Rcpp/algorithm.h:128:61: warning: 'long long' is a C++11 extension [-Wc++11-long-long]
        static CTYPE_UNSIGNED_LONG_LONG test(const unsigned long long &);
                                                            ^
6 warnings generated.

Using g++ with the same compiler flags, I do not get these warnings. Replacing long long and unsigned long long with rcpp_long_long_type and rcpp_ulong_long_type, respectively, seems to fix this. I can submit a PR if there are no objections with this approach.

[eddelbuettel]

Nice. I was honing in on a release but I think I'll take this one (and will of course run another set of rev.dep checks).

[thirdwing]

Fixed in #503