Re: Syntax Error

From:

Paul Bibbings <paul.bibbings@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Fri, 21 May 2010 20:21:58 +0100

Message-ID:

<87wruxrrft.fsf@gmail.com>

Peter Olcott <NoSpam@OCR4Screen.com> writes:

class FooListType {
  std::vector<FooType> Foos;
public:
  FooListType& operator+=( const FooListType& FooList );
  FooType& operator[](uint32 N){ return this->Foos[N]; };
  uint32 size(){ return Foos.size(); };
};

inline FooListType& FooListType::operator+=(const FooListType& FooList) {
  for (uint32 N = 0; N < FooList.size(); N++) // << Error is Here
    Foos.push_back(FooList[N]);
  return *this;
}

Points to line 11 above:
error C2662: 'FooListType::size' : cannot convert 'this' pointer from
const FooListType' to 'FooListType &' Conversion loses qualifiers

What am I doing wrong here?

1. (Germane to your actual error message) Neglecting to provide a const
   overload of your operator[] that can be called on a const object;
2. (Again) Neglecting to apply const correctness to FooListType::size()
   so that it, too, may be called on a const object;
3. Adding a number of stray `;'s in strange places;
4. Neglecting to provide a definition of FooType;
5. Using an unsigned integer type that is not available in C++03 and
   only optionally available in C++0x (not an error, but has portability
   implications.);
6. Omitting to provide a proper #include directive to make std::vector
   available so;
7. Omitting to provide code that is a complete, compilable example when
   seeking code-specific help (as per the FAQ for this newsgroup) -
   summarizing 4-6 inclusive.

Regards

Paul Bibbings