c++ - How to overload the new operator -

i tried overloading += get's me error :

expression must have integral or unscoped enum type

class sensor{}; class sensorlist{ sensor ** sensors; };  void main(){ sensor s1;  sensorlist *list = new sensorlist(); list += &s1;  } 

this overloading of += operator

sensorlist* operator+=(sensor * sens){          sensorlist * lista= new sensorlist();       sensor ** temp = new sensor*[this->noelem];     (int = 0; < this->noelem; i++)         temp[i] = this->senzori[i];      delete[] this->senzori;      this->senzori = new sensor*[this->noelem + 1];     (int = 0; < this->noelem; i++)         this->senzori[i] = temp[i];     this->senzori[this->noelem] = sens;      this->noelem += 1;      lista = this;            return lista; } 

how should it? have overload new operator?

however user defined operator+= of yours defined, both operands of

list += &s1; 

are pointers. never call user defined operator none of operands class or enum type. cannot overload operators 2 pointers because of language rules.

instead tries add pointer, , works integrals , enums, compiler tells you.

in particular, problem has nothing operator new, , apparently did not try overload that.

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so instead: stop doing through pointers , overload operators class or references class instead. this:

sensor s1; sensorlist sl; sl += s1; 

i recommend read this.

if really feel need use pointers (you shouldn't), use free function like

void add(sensorlist*, sensor*);