Try to fix things

glib_typeof wasn't defined in gmacros.h, so we never used the
better macros :(

glib/glib-typeof.h

@@ -24,8 +24,6 @@
 #error "Only <glib.h> can be included directly."
 #endif
 
-#include <glib/gversionmacros.h>
-
 /*
  * We can only use __typeof__ on GCC >= 4.8, and not when compiling C++. Since
  * __typeof__ is used in a few places in GLib, provide a pre-processor symbol
@@ -37,8 +35,7 @@
 #if !G_CXX_STD_CHECK_VERSION (11) && \
     (G_GNUC_CHECK_VERSION(4, 8) || defined(__clang__))
 #define glib_typeof(t) __typeof__ (t)
-#elif G_CXX_STD_CHECK_VERSION (11) && \
-      GLIB_VERSION_MIN_REQUIRED >= GLIB_VERSION_2_68
+#elif G_CXX_STD_CHECK_VERSION (11)
 /* C++11 decltype() is close enough for our usage */
 #include <type_traits>
 #define glib_typeof(t) typename std::remove_reference<decltype (t)>::type

glib/glibconfig.h.in

@@ -6,8 +6,6 @@
 #ifndef __GLIBCONFIG_H__
 #define __GLIBCONFIG_H__
 
-#include <glib/gmacros.h>
-
 #include <limits.h>
 #include <float.h>
 #mesondefine GLIB_HAVE_ALLOCA_H
@@ -26,7 +24,9 @@
  */
 #mesondefine GLIB_USING_SYSTEM_PRINTF
 
-G_BEGIN_DECLS
+#ifdef G_CXX_STD_VERSION
+extern "C" {
+#endif
 
 #define G_MINFLOAT	FLT_MIN
 #define G_MAXFLOAT	FLT_MAX
@@ -215,6 +215,8 @@ typedef @g_pid_type@ GPid;
 
 #mesondefine G_HAVE_FREE_SIZED
 
-G_END_DECLS
+#ifdef G_CXX_STD_VERSION
+}
+#endif
 
 #endif /* __GLIBCONFIG_H__ */

glib/gmacros.h

@@ -940,6 +940,8 @@
 #undef	ABS
 #undef	CLAMP
 
+#include "glib-typeof.h"
+
 #ifdef glib_typeof
 
 #define MAX(a, b) \