VS10中weak_ptr比较的问题

Question

我无法获得'operator＆lt;'使用VS10编译weak_ptr。我错过了#include或#using？

即使文档中的代码示例也不适用于我。 http://msdn.microsoft.com/en-us/library/bb982759.aspx

// temp.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"


// std_tr1__memory__operator_lt.cpp 
// compile with: /EHsc 
#include <memory> 
#include <iostream> 

int main() 
    { 
    std::shared_ptr<int> sp0(new int(0)); 
    std::shared_ptr<int> sp1(new int(0)); 

    std::cout << "sp0 < sp0 == " << std::boolalpha 
        << (sp0 < sp0) << std::endl; 
    std::cout << "sp0 < sp1 == " << std::boolalpha 
        << (sp0 < sp1) << std::endl; 
    std::cout << "sp1 < sp0 == " << std::boolalpha 
        << (sp1 < sp0) << std::endl; 
    std::cout << std::endl; 

    std::weak_ptr<int> wp0(sp0); 
    std::weak_ptr<int> wp1(sp1); 

    std::cout << "wp0 < wp0 == " << std::boolalpha 
        << (wp0 < wp0) << std::endl; 
    std::cout << "wp0 < wp1 == " << std::boolalpha 
        << (wp0 < wp1) << std::endl; 
    std::cout << "wp1 < wp0 == " << std::boolalpha 
        << (wp1 < wp0) << std::endl; 

    return (0); 
    } 

Answer 1

事实证明，头文件中没有未注释的'bool运算符＆lt;（const weak_ptr＆amp;，const weak_ptr＆amp;）。与文档相反，这是不受支持的。