variable length array issue for C++ API on CRAN

[fmichonneau]

In rncl, I use the C++ API of progress, and I got an email from CRAN saying they see the following warnings:

• with the clang compiler

   /home/hornik/tmp/R.check/r-devel-clang/Work/build/Packages/progress/include/RProgress.h:172:13: warning: variable length arrays are a C99 feature [-Wvla-extension]
   /home/hornik/tmp/R.check/r-devel-clang/Work/build/Packages/progress/include/RProgress.h:220:16: warning: variable length arrays are a C99 feature [-Wvla-extension] 
  

• on Windows:

d:/RCompile/CRANpkg/lib/3.4/progress/include/RProgress.h:172:27: warning: ISO C++ forbids variable length array 'bar' [-Wvla]
  d:/RCompile/CRANpkg/lib/3.4/progress/include/RProgress.h:220:26: warning: ISO C++ forbids variable length array 'spaces' [-Wvla]

[gaborcsardi]

Don't you just have to declare that you need a C++-11 compiler?

[fmichonneau]

I don't think it's enough, if I do this on my system:

clang++-3.9 -std=c++11 -I/usr/share/R/include -DNDEBUG -I. -DHAVE_INTTYPES_H -DASSERTS_TO_EXCEPTIONS -g -O3 -Wall -pedantic -mtune=native  -I"/home/francois/.R/library/Rcpp/include" -I"/home/francois/.R/library/progress/include"   -fpic  -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -g -c test.cpp -o test.o

I get same warnings

[hadley]

I see this too.