text: # =============================================================================
  #  https://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx_14.html
  # =============================================================================
  #
  # SYNOPSIS
  #
  #   AX_CXX_COMPILE_STDCXX_14([ext|noext], [mandatory|optional])
  #
  # DESCRIPTION
  #
  #   Check for baseline language coverage in the compiler for the C++14
  #   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
  #   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
  #   download the ax_cxx_compile_stdcxx.m4 file.
  #
  # LICENSE
  #
  #   Copyright (c) 2015 Moritz Klammler <moritz@klammler.eu>
  #
  #   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
  
  AX_REQUIRE_DEFINED([AX_CXX_COMPILE_STDCXX])
  AC_DEFUN([AX_CXX_COMPILE_STDCXX_14], [AX_CXX_COMPILE_STDCXX([14], [$1], [$2])])
  