configure: use C++17 as the only standard

The entire C++ code base has switched to using the gnu++17 standard so
update the check in configure.ac.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

diff --git a/configure.ac b/configure.ac
index 67c4f3c9929f1f999a6a0baac5fdad3f36ce1c18..8e430ea36dcf5b84f51b3d039893381cb5e3df14 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -181,7 +181,7 @@ if test "x$with_bindings_cxx" = xtrue
 then
        LT_LANG([C++])
        # This needs autoconf-archive
-       AX_CXX_COMPILE_STDCXX_11([ext], [mandatory])
+       AX_CXX_COMPILE_STDCXX_17([ext], [mandatory])
 
        if test "x$with_tests" = xtrue
        then
@@ -191,12 +191,6 @@ then
                        AC_LANG_POP([C++])
                ])
        fi
-
-       if test "x$with_examples" = xtrue
-       then
-               # Examples use C++17 features
-               AX_CXX_COMPILE_STDCXX([17], [ext], [mandatory])
-       fi
 fi
 
 AC_ARG_ENABLE([bindings-python],