# HG changeset patch
# User Markus Mützel <markus.muetzel@gmx.de>
# Date 1709313379 -3600
# Node ID fe201b17eb8644da72a3803a0579904db5fa93c5
# Parent  2c8ade2c749110efa6b8230e23ad35e0607527ab
build: Skip step that checks for C++11 flags during configuration (bug #65327).

* configure.ac: Use (un-documented) workaround to skip autotools test for
compiler flags that enable C++11 support. That test is broken for compilers
that are C++20-compliant.

diff -r 2c8ade2c7491 -r fe201b17eb86 configure.ac
--- a/configure.ac	Sat Mar 02 12:15:17 2024 +0100
+++ b/configure.ac	Fri Mar 01 18:16:19 2024 +0100
@@ -302,6 +302,14 @@
 
 ### Determine which C++ compiler to use (we expect to find g++ or clang++).
 
+# AC_PROG_CXX attempts to find the compiler flags for activating support for
+# C++11.  As of autoconf version 2.71, the source code that it uses for that
+# test includes parts that are invalid in C++20.
+# We are using AX_CXX_COMPILE_STDCXX to determine the potentially needed flags
+# for the C++ version that Octave requires.  So, skip the (unnecessary and
+# broken) test for C++11 in AC_PROG_CXX by setting the following (undocumented)
+# flag:
+ac_cv_prog_cxx_cxx11=""
 AC_PROG_CXX
 AC_PROG_CXXCPP