C ++模板类中的equal_to用法

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我对如何使用此方法感到困惑。我尝试了以下方法：

std::equal_to(T objA, T objB);

如果这样使用我会出错。但是，我看到了无数使用它的示例，例如：

pairs1 = mismatch(v1.begin(), v1.end(), 
                  v2.begin(), 
                  equal_to<int>());

应该如何使用此方法？

样本错误：

prog.cpp: In function ‘int main()’:
prog.cpp:25:31: error: no matching function for call to ‘std::equal_to<int>::equal_to(std::vector<int>&, std::vector<int>&)’
  pairs1 = equal_to<int>(v2, v1)); 
                               ^
In file included from /usr/include/c++/5/string:48:0,
                 from /usr/include/c++/5/random:40,
                 from /usr/include/c++/5/bits/stl_algo.h:66,
                 from /usr/include/c++/5/algorithm:62,
                 from prog.cpp:2:
/usr/include/c++/5/bits/stl_function.h:352:12: note: candidate: constexpr std::equal_to<int>::equal_to()
     struct equal_to : public binary_function<_Tp, _Tp, bool>
            ^
/usr/include/c++/5/bits/stl_function.h:352:12: note:   candidate expects 0 arguments, 2 provided
/usr/include/c++/5/bits/stl_function.h:352:12: note: candidate: constexpr std::equal_to<int>::equal_to(const std::equal_to<int>&)
/usr/include/c++/5/bits/stl_function.h:352:12: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/5/bits/stl_function.h:352:12: note: candidate: constexpr std::equal_to<int>::equal_to(std::equal_to<int>&&)
/usr/include/c++/5/bits/stl_function.h:352:12: note:   candidate expects 1 argument, 2 provided