导出类宏定义

#ifndef G_DECL_EXPORT

#ifdef WIN32

#define G_DECL_EXPORT __declspec(dllexport)

#else

#define G_DECL_EXPORT __attribute__((visibility("default")))

#endif

#endif

#ifndef G_DECL_IMPORT

#ifdef WIN32

#define G_DECL_IMPORT __declspec(dllimport)

#else

#define G_DECL_IMPORT

#endif

#endif

#ifdef DLL_OUT

#define DLL_CLASS G_DECL_EXPORT

#else

#define DLL_CLASS G_DECL_IMPORT

#endif