c++ - Use the parent class's function with the same name and aruments -

i have following classes:

class cpolygon {   spolygon* data; // populated constructor   // ... members here ... public:   cpolygon();   cpolygon(int type);   spolygon getdata(int index);   // ... methods here ... };  class csquare : public cpolygon {   // ... members here ... public:   csquare();   ssquare getdata(int index);   // ... methods here ... }; 

the second cpolygon() constructor accepts type of polygon want.

is there way call (second) constructor on csquare() constructor passing value square type, like:

csquare::csquare() {   cpolygon(type_square); } 

to make data square?

edit

i added new member , method/function. structure (and union):

union spolygon {   shead   head;   ssquare square;   // ... more structure here ... }  struct ssquare {   shead head;   // ... more membere here ... } 

i want return square data:

ssquare csquare::getdata(int index) {   return getdata(index).square; } 

but getdata() (inside function) considered csquare's need cpolygon's. how?

you can use member initialization list:

csquare::csquare(): cpolygon(type_square) {} 

this invokes cpolygon's constructor first, according correct type, csquare() constructor body executed.

note: initialization lists apply not super-classes, ordinary class members. examples, please refer c++ member initialization list.

for edited question, use cpolygon::getdata call specified version of getdata:

ssquare csquare::getdata(int index) {   return cpolygon::getdata(index).square; }