Enable c++11 syntax.

This requires a few fixes:
- Replace -ansi with -std=c++11 in autoconf.
- Add a check that c++11 is supported in autoconf.
- Change flags for cppcheck.
- Remove travis configurations that would fail.

Additionally, I removed the check for 'explicit' keyword,
which is not needed with C++11.

Fixes #212

.travis.yml

@@ -30,11 +30,6 @@ matrix:
     dist: trusty
     sudo: required
     env: PLUMED_CC=gcc   PLUMED_CXX=g++     PLUMED_CXXFLAGS=-O3 LAPACK=yes
-# then I try serial compiler on UBUNTU precise
-  - os: linux
-    dist: precise
-    sudo: required
-    env: PLUMED_CC=gcc   PLUMED_CXX=g++
 # test using external blas with internal lapack
   - os: linux
     dist: trusty

configure

@@ -4443,9 +4443,9 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 
 
   save_CXXFLAGS="$CXXFLAGS"
-  CXXFLAGS="$CXXFLAGS -ansi"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -ansi" >&5
-$as_echo_n "checking whether $CXX accepts -ansi... " >&6; }
+  CXXFLAGS="$CXXFLAGS -std=c++11"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -std=c++11" >&5
+$as_echo_n "checking whether $CXX accepts -std=c++11... " >&6; }
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -5056,11 +5056,15 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 
 fi
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports explicit" >&5
-$as_echo_n "checking whether $CXX supports explicit... " >&6; }
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX declares c++11 support" >&5
+$as_echo_n "checking whether $CXX declares c++11 support... " >&6; }
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
- class A{explicit A(){}};
+
+#if __cplusplus <= 199711L
+this_compiler_does_not_support_cxx11
+#endif
+
 int
 main ()
 {
@@ -5075,13 +5079,14 @@ $as_echo "yes" >&6; }
 else
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; } ;
-   $as_echo "#define explicit /**/" >>confdefs.h
-
+   as_fn_error $? "C++11 support is required" "$LINENO" 5
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 
 
 
+
+
 if test "$dependency_tracking" = true
 then
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX can generate dependency file with -MM -MF" >&5

configure.ac

@@ -252,7 +252,7 @@ if test $basic_warnings == true
 then
   PLUMED_CHECK_CXXFLAG([-Wall])
   PLUMED_CHECK_CXXFLAG([-pedantic])
-  PLUMED_CHECK_CXXFLAG([-ansi])
+  PLUMED_CHECK_CXXFLAG([-std=c++11])
 fi
 
 if test $debug == true
@@ -282,11 +282,17 @@ then
   PLUMED_CHECK_CXXFLAG([-Wold-style-cast])
 fi
 
-AC_MSG_CHECKING([whether $CXX supports explicit])
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([ class A{explicit A(){}};])],
+AC_MSG_CHECKING([whether $CXX declares c++11 support])
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([
+#if __cplusplus <= 199711L
+this_compiler_does_not_support_cxx11
+#endif
+])],
   [AC_MSG_RESULT([yes])],
   [AC_MSG_RESULT([no]) ;
-   AC_DEFINE([explicit],[])])
+   AC_MSG_ERROR([C++11 support is required])])
+
+
 
 AC_SUBST(disable_dependency_tracking)
 

src/maketools/codecheck

@@ -34,7 +34,7 @@ if [ $do_cppcheck == true ] ; then
   else
     files="$(echo */*.{h,cpp})"
   fi
-  cppcheck --std=c++03 --std=posix 4 -j 4 --platform=unix64 \
+  cppcheck --std=c++11 --std=posix 4 -j 4 --platform=unix64 \
   --template='[{file}:{line}] ({severity}) :{id}: {message}' --enable=all --inline-suppr --force \
   $files
 fi