template problem

// Apparently this has to go right at the top#define GL_GLEXT_PROTOTYPES#include <GL/gl.h>#include <GL/glu.h>#include <GL/glext.h>#ifndef VBO_H#define VBO_H#include <vector>...    template <typename T>    class Buffer    {        protected:            unsigned int m_id;            unsigned int m_type;            BufferNode m_node;            unsigned int m_usage;            static int s_supported;            // Check if VBOs are supported            static void checkSupported()            {                // Get Extensions String                std::string extensions = ((char const *)(glGetString(GL_EXTENSIONS)));                // Search The Extensions String For An Exact Copy                size_t found = extensions.find("GL_ARB_vertex_buffer_object");                if (found != std::string::npos)                    s_supported = 1;                s_supported = -1;            };        public:            // Get the value of s_supported            static bool isSupported()            {                if (!s_supported)                    checkSupported();                return s_supported == 1;            };            Buffer(unsigned int type, unsigned int size, unsigned int usage) :            m_id(0), m_type(type), m_node(0, size - 1), m_usage(usage)            {                // Make the buffer                glGenBuffersARB(1, &m_id);                bind();                glBufferDataARB(m_type, sizeof(T) * getSize(), 0, m_usage);                unbind();            };            ~Buffer()            {                if (m_id)                    glDeleteBuffersARB(1, &m_id);            };            unsigned int getId()            {                return m_id;            };            BufferNode* getNode()            {                return &m_node;            };            unsigned int getSize()            {                return m_node.getSize();            };            unsigned int getUsage()            {                return m_usage;            };            void bind()            {                glBindBufferARB(m_type, m_id);            };            void unbind()            {                glBindBufferARB(m_type, 0);            };            bool subData(BufferNode* node, unsigned int size, T* data)            {                if (!node || node->getSize() < size)                    return false;                bind();                glBufferSubDataARB(m_id, node->getFirst(), size, data);                unbind();                return true;            };    };