C++ 增压蓄能器可以用作类成员吗
我试着用一个升压累加器来计算一个滚动平均值。当我像这样内联声明变量时:C++ 增压蓄能器可以用作类成员吗,c++,boost,boost-accumulators,C++,Boost,Boost Accumulators,我试着用一个升压累加器来计算一个滚动平均值。当我像这样内联声明变量时: #include <iostream> #include <boost/accumulators/accumulators.hpp> #include <boost/accumulators/statistics/stats.hpp> #include <boost/accumulators/statistics/rolling_mean.hpp> using namespa
#include <iostream>
#include <boost/accumulators/accumulators.hpp>
#include <boost/accumulators/statistics/stats.hpp>
#include <boost/accumulators/statistics/rolling_mean.hpp>
using namespace boost::accumulators;
int main()
{
// Define rolling_mean accumulator
accumulator_set<double, stats<tag::rolling_mean > > acc(tag::rolling_window::window_size = 5);
// push in some data ...
acc(1.2);
acc(2.3);
acc(3.4);
acc(4.5);
// Display the results ...
std::cout << "Mean: " << rolling_mean(acc) << std::endl;
return 0;
}
此问题的正确解决方案是:
#include <iostream>
#include <boost/accumulators/accumulators.hpp>
#include <boost/accumulators/statistics/stats.hpp>
#include <boost/accumulators/statistics/rolling_mean.hpp>
using namespace boost::accumulators;
class DoMean {
private:
accumulator_set<double, stats<tag::rolling_mean > > m_acc;
public:
DoMean(void): m_acc(tag::rolling_window::window_size = 5) {}
void addData(double val) {
this->m_acc(val);
}
double getMean(void) {
return rolling_mean(this->m_acc);
}
};
int main()
{
// Define an accumulator set for calculating the mean and the
// 2nd moment ...
DoMean meaner;
meaner.addData(1.2);
meaner.addData(2.3);
meaner.addData(3.4);
meaner.addData(4.5);
// push in some data ...
// Display the results ...
std::cout << "Mean: " << meaner.getMean() << std::endl;
return 0;
}
我认为C++11允许这样做,我在代码中进行成员初始化。
accumulators::tag::rolling_window::window_size is not a type
...blah blah, many type template errors etc.
#include <iostream>
#include <boost/accumulators/accumulators.hpp>
#include <boost/accumulators/statistics/stats.hpp>
#include <boost/accumulators/statistics/rolling_mean.hpp>
using namespace boost::accumulators;
class DoMean {
private:
accumulator_set<double, stats<tag::rolling_mean > > m_acc;
public:
DoMean(void): m_acc(tag::rolling_window::window_size = 5) {}
void addData(double val) {
this->m_acc(val);
}
double getMean(void) {
return rolling_mean(this->m_acc);
}
};
int main()
{
// Define an accumulator set for calculating the mean and the
// 2nd moment ...
DoMean meaner;
meaner.addData(1.2);
meaner.addData(2.3);
meaner.addData(3.4);
meaner.addData(4.5);
// push in some data ...
// Display the results ...
std::cout << "Mean: " << meaner.getMean() << std::endl;
return 0;
}
#include <iostream>
class TestInit {
public:
int m_init = 10;
};
int main() {
TestInit inits;
std::cout << "The value: " << inits.m_init << std::endl;
}
/home/me/prog/cpp/acctest/testinit.cxx:5:16: error: ISO C++ forbids initialization of member m_init [-fpermissive]
/home/me/prog/cpp/acctest/testinit.cxx:5:16: error: making m_init static [-fpermissive]
/home/me/prog/cpp/acctest/testinit.cxx:5:16: error: ISO C++ forbids in-class initialization of non-const static member m_init