Why does Foo.h need to be included in Bar.cpp for this program to compile
properly? I define the FooList destructor in a separate module so that a
forward declaration to Foo can be used.


// FooList.h

#include <vector>

class Foo;

class FooList
{
std::vector<Foo> v;

public:
~FooList(); // destructor interface
};


// FooList.cpp

#include "FooList.h"
#include "Foo.h" // destructor definition this

FooList::~FooList() { }// destructor definition


// Bar.cpp

#include "FooList.h"

int main()
{
FooList foos;

return 0;
}


Error Message
==========

Bar.cpp
c:\program files\microsoft visual studio\vc98\include\vector(59): error
C2036: 'Foo *': unknown size
c:\program files\microsoft visual studio\vc98\include\vector(58): while
compiling class-template member function 'vector<Foo>::~vector<Foo>(void)'


I don't want to include Foo.h in Bar.cpp unless I have to. Do I have to? If
so, why? Thanks a bunch.