--- gigedit/trunk/configure.ac	2018/02/10 12:01:09	3419
+++ gigedit/trunk/configure.ac	2019/10/24 13:12:52	3637
@@ -5,7 +5,7 @@
 
 m4_define(gigedit_ver_major, 1)
 m4_define(gigedit_ver_minor, 1)
-m4_define(gigedit_ver_release, 0.svn6)
+m4_define(gigedit_ver_release, 1.svn6)
 
 AC_INIT([gigedit], [gigedit_ver_major.gigedit_ver_minor.gigedit_ver_release])
 AC_CONFIG_SRCDIR([configure.ac])
@@ -70,6 +70,12 @@
 AM_CONDITIONAL(WINDOWS, test "$windows" = "yes")
 AM_CONDITIONAL(MAC, test "$mac" = "yes")
 
+# make sure C++11 is supported by compiler
+# (add CXXFLAGS if required [e.g. -std=c++11])
+m4_ifdef([m4_include(m4/ax_cxx_compile_stdcxx.m4)],,
+             [sinclude([m4/ax_cxx_compile_stdcxx.m4])])
+AX_CXX_COMPILE_STDCXX(11, [], mandatory)
+
 # Note: even though Objective-C sources are just compiled for Mac, the
 # following AC macros though must not be embedded into a shell check
 # (if test "$mac" = "yes" ...), because those AC macros themselves are
@@ -77,7 +83,11 @@
 # code though would then not be executed and would lead to interesting
 # libtool errors on non-Mac systems due to this.
 AC_PROG_OBJC
-AC_PROG_OBJCXX
+# The OBJCXX macro didn't exist before autoconf 2.65, so ifdef it to
+# avoid warnings on old systems.
+m4_ifdef([AC_PROG_OBJCXX], [AC_PROG_OBJCXX])
+
+m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
 
 PKG_CHECK_EXISTS(gtk+-3.0 >= 2.99,
         [PKG_CHECK_MODULES([GTK], [gtk+-3.0])],
@@ -90,11 +100,18 @@
         [PKG_CHECK_MODULES(GTKMM, gtkmm-2.4 >= 2.8 gthread-2.0 cairomm-1.0)])
 AM_CONDITIONAL(HAVE_GTK3, [test "$have_gtk3" = "yes"])
 
+# Check for cairommconfig.h, as it was moved in cairomm 1.8.4. We only
+# need it for newer versions.
+gigedit_save_CPPFLAGS=$CPPFLAGS
+CPPFLAGS="$GTKMM_CFLAGS $CPPFLAGS"
+AC_CHECK_HEADERS([cairommconfig.h])
+CPPFLAGS=$gigedit_save_CPPFLAGS
+
 PKG_CHECK_MODULES(SIGC, sigc++-2.0)
 AC_SUBST(SIGC_CFLAGS)
 AC_SUBST(SIGC_LIBS)
 
-PKG_CHECK_MODULES(GIG, gig >= 4.1.0)
+PKG_CHECK_MODULES(GIG, gig >= 4.2.0)
 AC_SUBST(GIG_CFLAGS)
 AC_SUBST(GIG_LIBS)
 
@@ -104,7 +121,7 @@
 AC_SUBST(SNDFILE_LIBS)
 
 # check for (optional) presence of liblinuxsampler
-liblinuxsampler_version="2.1.0"
+liblinuxsampler_version="2.1.1"
 PKG_CHECK_MODULES(
     LINUXSAMPLER, linuxsampler >= $liblinuxsampler_version,
     have_linuxsampler=1, have_linuxsampler=0