accumulator.h

[詳解]

 
#pragma once
 
#include <new>
 
namespace ctrl {
 
template <typename T, std::size_t S>
class Accumulator {
 public:
  Accumulator(const T& value = T()) {
    buffer = new T[S];
    head = 0;
    clear(value);
  }
  ~Accumulator() { delete[] buffer; }
  void clear(const T& value = T()) {
    for (int i = 0; i < S; i++) buffer[i] = value;
  }
  void push(const T& value) {
    head = (head + 1) % S;
    buffer[head] = value;
  }
  const T& operator[](const std::size_t index) const {
    return buffer[(S + head - index) % S];
  }
  const T average(const int n = S) const {
    T sum = T();
    for (int i = 0; i < n; i++) {
      sum += buffer[(S + head - i) % S];
    }
    return sum / n;
  }
  std::size_t size() const { return S; }
 
 private:
  T* buffer; 
  std::size_t head; 
};
 
}  // namespace ctrl