visual studio 2010 - C++ Definition of dllimport static data member not allowed -

i trying compile source/headers of software static library, running dll issue. haven't been able run down, , standard #ifndef/#define _declspec(...) isn't working. don't have ton of c++ experience, i'm missing important. appreciated.

the errors occur on last 4 lines of section of source code, i'm not sure how fix it.

the header , source bit long here, jist:

header(.h):

#ifdef conversiondll_exports #define conversiondll_api __declspec(dllexport)  #else #define conversiondll_api __declspec(dllimport)  #endif  #ifndef conversionutility_h #define conversionutility_h  #include <config.h> #include <iostream> using namespace std;  #include <math.h> #include <stdio.h> #include <string>  #include <propertyfilehandler.h> #include <gwproperties.h> #include <puredatas.h> #include <puredatai.h>  class msr_export conversions {      msr::gwframework::component::propertyfilehandler propertyfilehandler_; double sea_level_corr_;      public:         double static const pi;         double static const degrees_per_radian;         double static const feet_per_meter;         unsigned short static rtcode_wgs_1984_identity;     ... 

source(.cpp):

#include <countdowntimer.h> #include "conversionutility.h" #include <rotation.h> #include <msrconversionerrorexception.h> #include <sstream> #include <stdlib.h> #include <ctime> #include <gwtime.h> #include <gwmanagerdefines.h>   double const conversions::pi = 3.14159265359; // low precision: atan(1.0)*4; double const conversions::degrees_per_radian = 180/pi; double const conversions::feet_per_meter = 1/0.3048; unsigned short conversions::rtcode_wgs_1984_identity = 341; // tena-tspi tdl