--- configure.ac.orig	2024-09-14 20:01:39 UTC
+++ configure.ac
@@ -47,40 +47,40 @@ fi
 fi
 
 # -ftree-vectorize
-AC_MSG_CHECKING([whether compiler supports -ftree-vectorize])
-old_CXXFLAGS="$CXXFLAGS"
-CXXFLAGS="-ftree-vectorize"
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ ]])],
-  AC_MSG_RESULT([yes])
-    tree_vectorize="-ftree-vectorize",
-  AC_MSG_RESULT([no])
-    tree_vectorize=""
-)
-CXXFLAGS="$old_CXXFLAGS $tree_vectorize"
+#AC_MSG_CHECKING([whether compiler supports -ftree-vectorize])
+#old_CXXFLAGS="$CXXFLAGS"
+#CXXFLAGS="-ftree-vectorize"
+#AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ ]])],
+#  AC_MSG_RESULT([yes])
+#    tree_vectorize="-ftree-vectorize",
+#  AC_MSG_RESULT([no])
+#    tree_vectorize=""
+#)
+#CXXFLAGS="$old_CXXFLAGS $tree_vectorize"
 
 # -ffast-math
-AC_MSG_CHECKING([whether compiler supports -ffast-math])
-old_CXXFLAGS="$CXXFLAGS"
-CXXFLAGS="-ffast-math"
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ ]])],
-  AC_MSG_RESULT([yes])
-    fast_math="-ffast-math",
-  AC_MSG_RESULT([no])
-    fast_math=""
-)
-CXXFLAGS="$old_CXXFLAGS $fast_math"
+#AC_MSG_CHECKING([whether compiler supports -ffast-math])
+#old_CXXFLAGS="$CXXFLAGS"
+#CXXFLAGS="-ffast-math"
+#AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ ]])],
+#  AC_MSG_RESULT([yes])
+#    fast_math="-ffast-math",
+#  AC_MSG_RESULT([no])
+#    fast_math=""
+#)
+#CXXFLAGS="$old_CXXFLAGS $fast_math"
 
 # -std=c++20
-AC_MSG_CHECKING([whether compiler supports -std=c++20])
-old_CXXFLAGS="$CXXFLAGS"
-CXXFLAGS="-std=c++20"
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ ]])],
-	AC_MSG_RESULT([yes])
-		std_cpp14="-std=c++20",
-	AC_MSG_RESULT([no])
-		AC_MSG_ERROR([[Your compiler doesn't seem to support C++20, please upgrade]])
-)
-CXXFLAGS="$old_CXXFLAGS $std_cpp14"
+#AC_MSG_CHECKING([whether compiler supports -std=c++20])
+#old_CXXFLAGS="$CXXFLAGS"
+#CXXFLAGS="-std=c++20"
+#AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ ]])],
+#	AC_MSG_RESULT([yes])
+#		std_cpp14="-std=c++20",
+#	AC_MSG_RESULT([no])
+#		AC_MSG_ERROR([[Your compiler doesn't seem to support C++20, please upgrade]])
+#)
+CXXFLAGS="$old_CXXFLAGS -std=c++17"
 
 # generic lambda expressions support
 AC_MSG_CHECKING([whether compiler supports generic lambda expressions])