Re: Overload of operator[]

From:
John Gilson <jag@acm.org>
Newsgroups:
comp.lang.c++
Date:
Tue, 26 Feb 2008 10:07:34 -0800 (PST)
Message-ID:
<3b5158a9-96f5-442d-b66d-9a2b300f17aa@o10g2000hsf.googlegroups.com>
On Feb 26, 7:55 am, Adrian <bitbuc...@bluedreamer.com> wrote:

I was trying to create a "readonly" operator[] in public scope and a
"write" operator[] in private scope of the class. But the compiler
seem intent on trying to use the private version.

Am I expecting to much from the compiler or is it not possible for it
to resolve the correct version of the function.

TIA

Adrian

dluadrianc:/home/adrianc> g++ -Wall -ansi -pedantic scope.cc
scope.cc: In function 'int main(int, char**)':
scope.cc:17: error: 'int& Container::operator[](size_t)' is private
scope.cc:31: error: within this context

#include <iostream>
#include <vector>

class Container : private std::vector<int>
{
   public:
      const int &operator[](size_t i) const
      {
         return (this->operator[](i));
      }
      using std::vector<int>::resize;
      void set(size_t t, int i)
      {
         this->operator[](t)=i;
      }
   private:
      int &operator[](size_t i)
      {
         return this->operator[](i);
      }

};


In addition to the indicated access problem during member function
resolution, you have an infinite loop in your attempted call of
operator[] defined in the base class, i.e., you'd have to write
std::vector<int>::operator[](i).

-- JAG

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