C++, removing #include or #include in class header

Question

I want to remove, if possible, the includes of both and from my class header file. Both string and vector are return types of functions declare

Answer 1

WARNING

Expect that doing this will cause uproar.

The language allows you to derive your own classes:

// MyKludges.h
#include 
#include 
class KludgeIntVector : public std::vector { 
  // ... 
};
class KludgeDoubleVector : public std::vector {
  // ...
};

class KludgeString : public std::string {
  // ...
};

Change your functions to return KludgeString and KludgeIntVector. Since these are no longer templates, you can forward declare them in your header files, and include MyKludges.h in your implementation files.

Strictly speaking, derived classes do not inherit base class constructors, destructors, assignment operators, and friends. You will need to provide (trivial) implementations of any that you're using.

---

// LotsOfFunctions.h
// Look, no includes!  All forward declared!
class KludgeString;
// 10,000 functions that use neither strings nor vectors
// ...
void someFunction(KludgeString &);
// ... 
// Another 10,000 functions that use neither strings nor vectors

// someFunction.cpp
// Implement someFunction in its own compilation unit
//  and  arrive on the next line
#include "MyKludges.h"
#include "LotsOfFunctions.h"
void someFunction(KludgeString &k) { k.clear(); }