XdbeQueryExtension(3X11)

     NAME
          XdbeQueryExtension - returns the version of DBE supported by
          the server.

     SYNOPSIS
          #include <X11/extensions/Xdbe.h>

          Status XdbeQueryExtension(
              Display *dpy,
              int     *major_version_return,
              int     *minor_version_return)

     DESCRIPTION
          Sets major_version_return and minor_version_return to the
          major and minor DBE protocol version supported by the
          server.  If the DBE library is compatible with the version
          returned by the server, this function returns non-zero.  If
          dpy does not support the DBE extension, or if there was an
          error during communication with the server, or if the server
          and library protocol versions are incompatible, this
          function returns zero.  No other Xdbe functions may be
          called before this function.  If a client violates this
          rule, the effects of all subsequent Xdbe calls that it makes
          are undefined.

     SEE ALSO
          DBE, XdbeAllocateBackBufferName(), XdbeBeginIdiom(),
          XdbeDeallocateBackBufferName(), XdbeEndIdiom(),
          XdbeFreeVisualInfo(), XdbeGetBackBufferAttributes(),
          XdbeGetVisualInfo(), XdbeSwapBuffers().