fix documentation of --enable-cxx-mode

diff --git a/INSTALL b/INSTALL
index 7a44ad8896a24dc20763deb05038d3a77b0dce7f..5c9c4d74899a13e6c632f9d5127a7e0536b49146 100644 (file)
--- a/INSTALL
+++ b/INSTALL
@@ -208,8 +208,8 @@ precisely (see the description of --enable-build-type for the default
 values):
 
   o --enable-cxx-mode=VALUE can be used to select a C++ standard, for
-    example --enable-cxx-mode=11. The default is to try C++14, and then
-    C++11.
+    example --enable-cxx-mode=11. The default is to try C++17, C++14, and
+    C++11, in this order.
 
   o --enable-optimization=VALUE enables you to set optimization to a
     higher level than the default, for example --enable-optimization=-O3.