bump to C++17

Signed-off-by: c8ef <c8ef@outlook.com>

Author: c8ef

.bazelrc

@@ -1 +1 @@
-build --conlyopt='-std=gnu11' --cxxopt='-std=gnu++14'
+build --conlyopt='-std=gnu11' --cxxopt='-std=gnu++17'

configure.ac

@@ -21,7 +21,7 @@ AC_PROG_CXX
 # built if --with-proto=yes)
 # if there is no C++ compiler available or if the C++ compiler doesn't support
 # std=c++11, configure will not fail
-AX_CXX_COMPILE_STDCXX_11([noext],[optional])
+AX_CXX_COMPILE_STDCXX([17], [noext], [optional])
 
 m4_define_default([_AM_PYTHON_INTERPRETER_LIST], [python3 python])
 AM_CONDITIONAL([HAVE_python], [test "$PYTHON" != :])

frontends_extra/cpp/configure.ac

@@ -16,7 +16,7 @@ AC_CONFIG_MACRO_DIR([m4])
 AC_LANG_PUSH(C)
 AC_LANG_PUSH(C++)
 
-AX_CXX_COMPILE_STDCXX_11([noext],[mandatory])
+AX_CXX_COMPILE_STDCXX([17], [noext], [mandatory])
 
 want_bmv2=no
 AC_ARG_WITH([bmv2],