COMP: style of update

configure

@@ -57,6 +57,9 @@ echo "ITKURL;${itkgit}" >> ../data/softwareVersions.csv
 mkdir -p itkb
 cd itkb
 compflags=" -fPIC -O2 -Wno-c++11-long-long "
+if [[ `uname` -eq Darwin ]] ; then
+    compflags=" ${compflags} -isystem /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/v1 -stdlib=libc++ "
+fi
 cmaker=`${R_HOME}/bin/Rscript -e "x=Sys.which('cmake'); cat(x)"`
 if [[ -z "${cmaker}" ]]; then
 	res=`${R_HOME}/bin/Rscript -e "cat(('cmaker' %in% installed.packages())*1)"`
@@ -76,7 +79,7 @@ ${cmaker} \
     -DCMAKE_CXX_STANDARD="17"\
     -DCMAKE_CXX_STANDARD_REQUIRED="YES"\
     -DCMAKE_C_FLAGS="${CMAKE_C_FLAGS} ${compflags} -DNDEBUG  "\
-    -DCMAKE_CXX_FLAGS="${CMAKE_CXX_FLAGS} ${compflags} -DNDEBUG -isystem /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/v1 -stdlib=libc++ "\
+    -DCMAKE_CXX_FLAGS="${CMAKE_CXX_FLAGS} ${compflags} -DNDEBUG  "\
     -DITK_USE_GIT_PROTOCOL:BOOL=OFF \
     -DBUILD_SHARED_LIBS=OFF \
     -DBUILD_TESTING:BOOL=OFF \