expr= (Debugger::Breakpoint)

    /*
     *   call-seq:
     *      breakpoint.expr = string
     *
     *   Sets the codition expression when this breakpoint should be activated.
     */
    static VALUE
    breakpoint_set_expr(VALUE self, VALUE value)
    {
        debug_breakpoint_t *breakpoint;

        Data_Get_Struct(self, debug_breakpoint_t, breakpoint);
        breakpoint->expr = StringValue(value);
        return value;
    }