以下代码总结了我的问题:templateclassBase{};templateclassDerived1:publicBase{};templateclassDerived2:publicBase{public://CopyconstructorDerived2(constDerived2&x);//AnEXPLICITconstructorthatdoesaspecialconversionforaDerived2//withothertemplateparameterstemplateexplicitDerived2(constDerived2&x);//Nowtheproble