/*
 *  call-seq:
 *     block_given?   => true or false
 *     iterator?      => true or false
 *  
 *  Returns <code>true</code> if <code>yield</code> would execute a
 *  block in the current context. The <code>iterator?</code> form
 *  is mildly deprecated.
 *     
 *     def try
 *       if block_given?
 *         yield
 *       else
 *         "no block"
 *       end
 *     end
 *     try                  #=> "no block"
 *     try { "hello" }      #=> "hello"
 *     try do "hello" end   #=> "hello"
 */


static VALUE
rb_f_block_given_p()
{
    if (ruby_frame->prev && ruby_frame->prev->iter == ITER_CUR && ruby_block)
        return Qtrue;
    return Qfalse;
}