I'm not sure if this is the right forum category for this(since linkage errors aren't only for DirectX)

The problem is,in my vertex declaration header:

#pragma once
#include <d3dx9.h>
void InitAllVertexDeclarations();
void DestroyAllVertexDeclarations();
struct VertexPos
{
VertexPos():pos(0.0f, 0.0f, 0.0f){}
VertexPos(float x, float y, float z):pos(x,y,z){}
VertexPos(const D3DXVECTOR3& v):pos(v){}
D3DXVECTOR3 pos;
static IDirect3DVertexDeclaration9* Decl;
};
struct VertexCol
{
VertexCol():pos(0.0f, 0.0f, 0.0f),col(0x00000000){}
VertexCol(float x, float y, float z, D3DCOLOR c):pos(x,y,z), col(c){}
VertexCol(const D3DXVECTOR3& v, D3DCOLOR c):pos(v),col(c){}
D3DXVECTOR3 pos;
D3DCOLOR col;
static IDirect3DVertexDeclaration9* Decl;
};
struct VertexPN
{
VertexPN()
:pos(0.0f, 0.0f, 0.0f),
normal(0.0f, 0.0f, 0.0f){}
VertexPN(float x, float y, float z,
float nx, float ny, float nz):pos(x,y,z), normal(nx,ny,nz){}
VertexPN(const D3DXVECTOR3& v, const D3DXVECTOR3& n)
:pos(v),normal(n){}
D3DXVECTOR3 pos;
D3DXVECTOR3 normal;
static IDirect3DVertexDeclaration9* Decl;
};
struct VertexPNT
{
VertexPNT()
:pos(0.0f, 0.0f, 0.0f),
normal(0.0f, 0.0f, 0.0f),
tex0(0.0f, 0.0f){}
VertexPNT(float x, float y, float z,
float nx, float ny, float nz,
float u, float v):pos(x,y,z), normal(nx,ny,nz), tex0(u,v){}
VertexPNT(const D3DXVECTOR3& v, const D3DXVECTOR3& n, const D3DXVECTOR2& uv)
:pos(v),normal(n), tex0(uv){}
D3DXVECTOR3 pos;
D3DXVECTOR3 normal;
D3DXVECTOR2 tex0;
static IDirect3DVertexDeclaration9* Decl;
};
IDirect3DVertexDeclaration9* VertexPos::Decl = 0;
IDirect3DVertexDeclaration9* VertexCol::Decl = 0;
IDirect3DVertexDeclaration9* VertexPN::Decl = 0;
IDirect3DVertexDeclaration9* VertexPNT::Decl = 0;


i have used


IDirect3DVertexDeclaration9* VertexPos::Decl = 0;
IDirect3DVertexDeclaration9* VertexCol::Decl = 0;
IDirect3DVertexDeclaration9* VertexPN::Decl = 0;
IDirect3DVertexDeclaration9* VertexPNT::Decl = 0;
and then the header is used by the Terrain header,which in turn is used by the Camera header.Now i checked all other possibilities,there is no other place where this problem could originate.The problem is IntelliSense says all these structs are alredy defined in the .obj-s where ''Vertex.h'' is used:

[attachment=8685:error.png]