c++ - Error attempting to reference a deleted function -

i want initialize enemy::copy using parameter passed initialization constructor, following error:

c2280: 'enemy &enemy::operator =(const enemy &)': attempting reference deleted function 

here declaration of class enemy:

 #include "pickup.h"  class enemy : public entity  {  private:         std::vector<pickup>& copy;  public:         enemy::enemy(std::vector<pickup>& arraypickup) : copy(arraypickup) {}   }; 

and code main():

std::vector<pickup> arraypickup; enemy enemy(arraypickup); 

how solve it?

this answer based on correct suggestion @praetorian.

short answer fix:

the issue in std::vector<pickup>& copy; member of enemy class. change std::vector<pickup> copy;, removing reference, fix error. indeed, there absolutely no need store vector reference, on contrary, can see, having reference members in class cause errors 1 you've faced. may have been confused fact vector passed reference initialization c'tor, in no way means should make class member reference.

if still want store enemy::copy data reference, e.g. performance issues, consider making pointer, so:

class enemy : public entity  {  private:         std::vector<pickup>* copy;  // rest of class...  }; 

long answer:

code reproduce issue:

class foo {     int& ri; public: //    default c'tor can't defined in sane fashion  because of reference member ri //    foo() : ri(0) {}     foo(int& _ri) : ri(_ri) {} };  int main(int argc, char **argv) {     int i{42};     foo f1{i};     foo f2{f1}; // don't have default constructor using auto-generated copy c'tor     f2 = f1; // <--- error     return 0; } 

results in error:

main.cpp: in function 'int main(int, char**)': main.cpp:14:12: error: use of deleted function 'foo& foo::operator=(const foo&)'          f2 = f1; // <--- error             ^ main.cpp:1:11: note: 'foo& foo::operator=(const foo&)' implicitly deleted                      because default definition ill-formed:      class foo            ^ main.cpp:1:11: error: non-static reference member 'int& foo::ri',                       can't use default assignment operator 

explanation:

an auto-generated operator=(), otherwise generated in case [1], considered ill-formed due fact can't reassign references in c++ [2]. auto-generated operator=(foo& other), should exist, attempt perform this->ri = other.ri, considered incorrect ("ill-formed", reported compiler), since it's re-assignment of reference ri.

finally, suggest see [3], in-depth answer on issue.

1. about auto-generated copy assignment operator

2. about re-assigning references

3. assignment operator , copy constructor in presence of references