Use and require C++17

configure.ac

@@ -39,7 +39,7 @@ LT_INIT
 PKG_PROG_PKG_CONFIG
 PKG_INSTALLDIR
 
-AX_CXX_COMPILE_STDCXX_14([ext],[mandatory])
+AX_CXX_COMPILE_STDCXX_17([ext],[mandatory])
 
 dnl turn on warnings
 [CXXFLAGS="-Wall -Wextra -ftemplate-backtrace-limit=0 ${CXXFLAGS}"]

m4/ax_cxx_compile_stdcxx_14.m4 → m4/ax_cxx_compile_stdcxx_17.m4

 # =============================================================================
-#  https://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx_14.html
+#  https://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx_17.html
 # =============================================================================
 #
 # SYNOPSIS
 #
-#   AX_CXX_COMPILE_STDCXX_14([ext|noext], [mandatory|optional])
+#   AX_CXX_COMPILE_STDCXX_17([ext|noext], [mandatory|optional])
 #
 # DESCRIPTION
 #
-#   Check for baseline language coverage in the compiler for the C++14
+#   Check for baseline language coverage in the compiler for the C++17
 #   standard; if necessary, add switches to CXX and CXXCPP to enable
 #   support.
 #
 #   This macro is a convenience alias for calling the AX_CXX_COMPILE_STDCXX
-#   macro with the version set to C++14.  The two optional arguments are
+#   macro with the version set to C++17.  The two optional arguments are
 #   forwarded literally as the second and third argument respectively.
 #   Please see the documentation for the AX_CXX_COMPILE_STDCXX macro for
 #   more information.  If you want to use this macro, you also need to
@@ -22,13 +22,14 @@
 # LICENSE
 #
 #   Copyright (c) 2015 Moritz Klammler <moritz@klammler.eu>
+#   Copyright (c) 2016 Krzesimir Nowak <qdlacz@gmail.com>
 #
 #   Copying and distribution of this file, with or without modification, are
 #   permitted in any medium without royalty provided the copyright notice
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 5
+#serial 2
 
 AX_REQUIRE_DEFINED([AX_CXX_COMPILE_STDCXX])
-AC_DEFUN([AX_CXX_COMPILE_STDCXX_14], [AX_CXX_COMPILE_STDCXX([14], [$1], [$2])])
+AC_DEFUN([AX_CXX_COMPILE_STDCXX_17], [AX_CXX_COMPILE_STDCXX([17], [$1], [$2])])