Xorg can not use C++ code with xf86.h, xf86_OSproc.h, xf86Cursor.h, cursorstr.h and others included

Xorg use some C++ reserved names such as class, bool and private as variable names and it causes conflicts.

In file included from /home/twaik/xf86-video-dummy/src/dummy_cursor.cpp:6:
In file included from /home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86.h:44:
In file included from /home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86str.h:39:
/home/twaik/xorg-server-1.20.1/include/scrnintstr.h:68:11: error: declaration of anonymous class must be a
      definition
    short class;
          ^
/home/twaik/xorg-server-1.20.1/include/scrnintstr.h:68:5: warning: declaration does not declare anything
      [-Wmissing-declarations]
    short class;
    ^~~~~
In file included from /home/twaik/xf86-video-dummy/src/dummy_cursor.cpp:6:
In file included from /home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86.h:44:
In file included from /home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86str.h:40:
/home/twaik/xorg-server-1.20.1/include/pixmapstr.h:59:19: error: declaration of anonymous class must be a
      definition
    unsigned char class;        /* specific to type */
                  ^
/home/twaik/xorg-server-1.20.1/include/pixmapstr.h:59:5: warning: declaration does not declare anything
      [-Wmissing-declarations]
    unsigned char class;        /* specific to type */
    ^~~~~~~~~~~~~
In file included from /home/twaik/xf86-video-dummy/src/dummy_cursor.cpp:6:
In file included from /home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86.h:44:
In file included from /home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86str.h:41:
/home/twaik/xorg-server-1.20.1/include/colormapst.h:91:11: error: declaration of anonymous class must be a
      definition
    short class;                /* PseudoColor or DirectColor */
          ^
/home/twaik/xorg-server-1.20.1/include/colormapst.h:91:5: warning: declaration does not declare anything
      [-Wmissing-declarations]
    short class;                /* PseudoColor or DirectColor */
    ^~~~~
In file included from /home/twaik/xf86-video-dummy/src/dummy_cursor.cpp:6:
In file included from /home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86.h:44:
In file included from /home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86str.h:43:
/home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86Opt.h:44:10: error: cannot combine with previous
      'type-name' declaration specifier
    Bool bool;
         ^
/home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86Opt.h:44:5: warning: declaration does not declare
      anything [-Wmissing-declarations]
    Bool bool;
    ^~~~~~~~~
In file included from /home/twaik/xf86-video-dummy/src/dummy_cursor.cpp:6:
In file included from /home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86.h:44:
/home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86str.h:482:52: error: expected ')'
typedef void (*EntityProc) (int entityIndex, void *private);
                                                   ^
/home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86str.h:482:28: note: to match this '('
typedef void (*EntityProc) (int entityIndex, void *private);
                           ^
In file included from /home/twaik/xf86-video-dummy/src/dummy_cursor.cpp:6:
/home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86.h:127:56: error: expected ')'
                                                 void *private);
                                                       ^
/home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86.h:121:49: note: to match this '('
extern _X_EXPORT ScrnInfoPtr xf86ConfigPciEntity(ScrnInfoPtr pScrn,
                                                ^
/home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86.h:332:62: error: expected ')'
                   EntityProc enter, EntityProc leave, void *private);
                                                             ^
/home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86.h:330:19: note: to match this '('
xf86ConfigFbEntity(ScrnInfoPtr pScrn, int scrnFlag,
                  ^
In file included from /home/twaik/xf86-video-dummy/src/dummy_cursor.cpp:12:
In file included from /home/twaik/xf86-video-dummy/src/dummy.h:11:
/home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86xv.h:116:11: error: declaration of anonymous class
      must be a definition
    short class;
          ^
/home/twaik/xorg-server-1.20.1/hw/xfree86/common/xf86xv.h:116:5: warning: declaration does not declare
      anything [-Wmissing-declarations]
    short class;
    ^~~~~
5 warnings and 8 errors generated.