Trying to create a vector of COORD, causes linking error - c++

Question

my code is:
#pragma once
#include "stdafx.h"
#include <vector>
#include "field.h"
class output
{
void putAtLocation(COORD, char chIcon); //currently this outputs to console
static std::vector<COORD> m_vsOutputBuffer;
public:
output(void);
static void addToken(COORD);
void drawTokens();
~output(void);
};
and the linker error is:
output.obj : error LNK2001: unresolved external symbol "private: static class std::vector<struct _COORD,class std::allocator<struct _COORD> > output::m_vsOutputBuffer" (?m_vsOutputBuffer#output##0V?$vector#U_COORD##V?$allocator#U_COORD###std###std##A)
this must be the problem line:
static std::vector<COORD> m_vsOutputBuffer;
I've been at this for hours stuck. I finally noticed that changing COORD to int causes the linker error to go away. I've read that it's(linker errors) are usually caused by dependency issues. But here it just changing a TYPE. I've also read it can be caused by using a function in a way it wasn't supposed to be. I figure it has to be the way is handling COORDs; or something about COORDS is forward declared, or referenced in output.cpp properly.
Edit:
all changing to int did was make compiler errors that caused it never to hit the linker. now I am back to nothing
and the cpp file:
#include "stdafx.h"
#include "output.h"
#include <vector>
static std::vector<int> m_vsOutputBuffer;
output::output(void)
{
}
void output::addToken(COORD sCoordinate) //mark a coord in the buffer as needing refreshed
{
m_vsOutputBuffer.push_back(sCoordinate);
}
void output::drawTokens() //release the outputbuffer the the output window
{
for (unsigned int iii = 0; iii < m_vsOutputBuffer.size(); iii++)
{
putAtLocation(m_vsOutputBuffer[iii], field::checkHit( m_vsOutputBuffer[iii] ) );
}
}
void output::putAtLocation(COORD sCoordinate, char chIcon) //outputs a single character to the console
{
DWORD dwNumWritten = 0;
LPDWORD lpdNumWritten = &dwNumWritten;
WriteConsoleOutputCharacter(
GetStdHandle( STD_OUTPUT_HANDLE ), //***repeatedly getting this handle may end up a bottleneck
LPCTSTR(&chIcon),
1,
sCoordinate,
lpdNumWritten
);
}
output::~output(void)
{
}
also I found this: http://www.cplusplus.com/forum/general/6111/
so I tried moving the static statement to the cpp file and it compiled and ran. but not its not a member variable. So I Need to somehow forward declare the vector.(before the declaration was also creating the static object in the header file.

Answer 1

you need this line in your .cpp file:
std::vector<COORD> output::m_vsOutputBuffer;
(Note the absence of static and the scope output::)
This is the actual definition of the member variable. What you have in the class (.h) is only the declaration.
Without this the static variable output:m_vsOutputBuffer does not exist and the linker rightfully complains that it can't find it.

Answer 2

Coord is defined in windows.h header... Look into stdafx.h if there is something like
#include <windows.h>.
Other than that I tried to copy your code add this header and compile it.. went smooth
To edited version:
You probably forgot to change
static std::vector<int> m_vsOutputBuffer;
back to
static std::vector<COORD> m_vsOutputBuffer;
But I assume you had it that way before.. Second thing is that you don't have to include the same headers in header and cpp file but this is not causing it.. It is the line in cpp file with
static std::vector<COORD> m_vsOutputBuffer;
change it just to:
std::vector<COORD> output::m_vsOutputBuffer;
You can read on why in this text:
http://publib.boulder.ibm.com/infocenter/comphelp/v8v101/index.jsp?topic=%2Fcom.ibm.xlcpp8a.doc%2Flanguage%2Fref%2Fcplr038.htm
Simply said you need do define not just declare.