boost accumulator_set:预期的主要表达
boost accumulator_set: expect primary expression
我是 Boost 库的新手。我想要一个可以计算距离向量(std::vector < double >
类型)的最小值、最大值、均值和方差的程序,我编写了以下代码
std::vector < double > dist_err;
// ... do something with dist_err
boost::accumulators::accumulator_set
<
double,
boost::accumulators::stats
<
boost::accumulators::tag::min ,
boost::accumulators::tag::max ,
boost::accumulators::tag::mean,
boost::accumulators::tag::variance
>
> stat_acc;
std::for_each(dist_err.begin(), dist_err.end(), boost::bind < void > (boost::ref(stat_acc), boost::mpl::placeholders::_1));
std::cout << "min[distance error]: " << boost::accumulators::min (stat_acc) << std::endl;
std::cout << "MAX[distance error]: " << boost::accumulators::max (stat_acc) << std::endl;
std::cout << " E[distance error]: " << boost::accumulators::mean (stat_acc) << std::endl;
std::cout << "VAR[distance error]: " << boost::accumulators::variance (stat_acc) << std::endl;
但是程序在第 std::for_each(dist_err.begin(), dist_err.end(), boost::bind < void > (boost::ref(stat_acc), boost::mpl::placeholders::_1));
行给我一个错误,它说
error: expected primary-expression before ')' token
std::for_each(dist_err.begin(), dist_err.end(), boost::bind < void > (boost::ref(stat_acc), boost::mpl::placeholders::_1));
有人可以给我一些解决此错误的提示吗?
问题是您在不使用 MPL 的内部代码中使用 boost::mpl::placeholders::_1
。相反,只需说 _1
.
我是 Boost 库的新手。我想要一个可以计算距离向量(std::vector < double >
类型)的最小值、最大值、均值和方差的程序,我编写了以下代码
std::vector < double > dist_err;
// ... do something with dist_err
boost::accumulators::accumulator_set
<
double,
boost::accumulators::stats
<
boost::accumulators::tag::min ,
boost::accumulators::tag::max ,
boost::accumulators::tag::mean,
boost::accumulators::tag::variance
>
> stat_acc;
std::for_each(dist_err.begin(), dist_err.end(), boost::bind < void > (boost::ref(stat_acc), boost::mpl::placeholders::_1));
std::cout << "min[distance error]: " << boost::accumulators::min (stat_acc) << std::endl;
std::cout << "MAX[distance error]: " << boost::accumulators::max (stat_acc) << std::endl;
std::cout << " E[distance error]: " << boost::accumulators::mean (stat_acc) << std::endl;
std::cout << "VAR[distance error]: " << boost::accumulators::variance (stat_acc) << std::endl;
但是程序在第 std::for_each(dist_err.begin(), dist_err.end(), boost::bind < void > (boost::ref(stat_acc), boost::mpl::placeholders::_1));
行给我一个错误,它说
error: expected primary-expression before ')' token
std::for_each(dist_err.begin(), dist_err.end(), boost::bind < void > (boost::ref(stat_acc), boost::mpl::placeholders::_1));
有人可以给我一些解决此错误的提示吗?
问题是您在不使用 MPL 的内部代码中使用 boost::mpl::placeholders::_1
。相反,只需说 _1
.