Hi Shuai, On 06/13/14 06:26, Shuai Meng wrote: > - hres = to_string(arg, &str); > + assert(args_cnt == 1); > + > + V_VT(&v) = VT_EMPTY; > + hres = VariantChangeType(&v, arg, VARIANT_LOCALBOOL, VT_BSTR); Why do you change it? to_string() already does the same call. Jacek