vs2008条件编译不能用？解决办法

#ifndef _COMMON_H_
#define _COMMOM_H_
#include <queue>
using std::queue;

enum direct { east=1,north=2,west=3,south=4 };

template<class T>
class LimitQueue
{
private:
    unsigned int length;
    queue<T> container;
public:
    LimitQueue(unsigned int)
    {
        this->length=i;
    }
    bool push(T element)
    {
        if(container.size()<length)
        {
            container.push(element);
            return true;
        }
        else
        {
            return false;
        }
    }
    T front()
    {
        return container.front();
    }
    void pop()
    {
        container.pop();
    }
};

#endif