fix boost.system for boost >= 1.70 (header only)

gerlachs · tsuna · commit 8d9ceb2dc545 · 2025-01-21T16:15:06.000+01:00
diff --git a/build-aux/boost.m4 b/build-aux/boost.m4
@@ -1332,11 +1332,17 @@ BOOST_DEFUN([String_Algo],
 # --------------------------------
 # Look for Boost.System.  For the documentation of PREFERRED-RT-OPT, see the
 # documentation of BOOST_FIND_LIB above.  This library was introduced in Boost
-# 1.35.0.
+# 1.35.0 and is header only since 1.70.
 BOOST_DEFUN([System],
-[BOOST_FIND_LIB([system], [$1],
+[
++[
+if test $boost_major_version -ge 170; then
+  BOOST_FIND_HEADER([boost/system/error_code.hpp])
+else
+  BOOST_FIND_LIB([system], [$1],
                 [boost/system/error_code.hpp],
                 [boost::system::error_code e; e.clear();], [], [], [$2])
+fi
 ])# BOOST_SYSTEM
 
 
