boost :: lambda表达式无法编译

Question

我尝试编写一个函数,使用boost lambda库计算两个代码字之间的汉明距离.我有以下代码:

#include <iostream>
#include <numeric>
#include <boost/function.hpp>
#include <boost/lambda/lambda.hpp>
#include <boost/lambda/if.hpp>
#include <boost/bind.hpp>
#include <boost/array.hpp>

template<typename Container>
int hammingDistance(Container & a, Container & b) {
  return std::inner_product(
    a.begin(),
    a.end(),
    b.begin(),
    (_1 + _2),
    boost::lambda::if_then_else_return(_1 != _2, 1, 0)
  );
}

int main() {
  boost::array<int, 3> a = {1, 0, 1}, b = {0, 1, 1};
  std::cout << hammingDistance(a, b) << std::endl;
}

而我得到的错误是:

HammingDistance.cpp: In function ‘int hammingDistance(Container&, Container&)’:
HammingDistance.cpp:15: error: no match for ‘operator+’ in ‘<unnamed>::_1 + <unnamed>::_2’
HammingDistance.cpp:17: error: no match for ‘operator!=’ in ‘<unnamed>::_1 != <unnamed>::_2’
/usr/include/c++/4.3/boost/function/function_base.hpp:757: note: candidates are: bool boost::operator!=(boost::detail::function::useless_clear_type*, const boost::function_base&)
/usr/include/c++/4.3/boost/function/function_base.hpp:745: note:                 bool boost::operator!=(const boost::function_base&, boost::detail::function::useless_clear_type*)

这是我第一次玩boost lambda.请告诉我哪里出错了.谢谢.

编辑:

非常感谢!这是工作代码(仅供参考):

#include <iostream>
#include <numeric>
#include <boost/function.hpp>
#include <boost/lambda/lambda.hpp>
#include <boost/lambda/if.hpp>
#include <boost/lambda/bind.hpp>
#include <boost/array.hpp>

using boost::lambda::_1;
using boost::lambda::_2;

template<typename Container>
int hammingDistance(Container & a, Container & b) {
  return std::inner_product(
    a.begin(),
    a.end(),
    b.begin(),
    0,
    (_1 + _2),
    boost::lambda::if_then_else_return(_1 != _2, 1, 0)
  );
}

int main() {
  boost::array<int, 3> a = {1, 0, 1}, b = {0, 1, 1};
  std::cout << hammingDistance(a, b) << std::endl;
}

Answer 1

第一个问题:使用时boost/lambda,包括<boost/lambda/bind.hpp>代替<boost/bind.hpp>

第二个问题:你需要using namespace boost::lambda在#includes之后

仍然不编译

编辑:
第三个问题 - 你需要6个参数std::inner_product,你错过了一个初始化参数.可能会加上0第四个论点.