mincongzhang

Implement a simple shared_ptr from scratch

There is a lot to consider if we want to implement a shared_ptr from scratch, but we can break it down into basic constructors, copy sematics, move sematics and eventually destructor to make it easier.

Let's follow the following structure and see how to do it.

Basic constructors

Firstly we can just add the basic members and constructors:

mincongzhang

//https://chrizog.com/cpp-thread-synchronization

#include <chrono>
#include <future>
#include <iostream>
#include <thread>
#include <vector>
struct Packet {
  int id;
};

mincongzhang

def get_stamp_duty(price, first_time_buyer):
  stamp_duty = 0
  not_first_time_rate = 0.0 if first_time_buyer else 0.03
  if price < 125000:
    stamp_duty += price*(0+not_first_time_rate)
  elif price < 250000:
    stamp_duty += 125000*(0+not_first_time_rate)
    stamp_duty += (price-125000)*(0.02+not_first_time_rate)
  elif price < 925000:
    stamp_duty += 125000*(0+not_first_time_rate)

mincongzhang

import pandas as pd
#@register_type
class DataFrameWrapper:
    #@register_method
    def __init__(self):
        self.m_df =\
        pd.DataFrame([["day1","day2","day1","day2","day1","day2"],
                      ["A","B","A","B","C","C"],
                      [100,150,200,150,100,50],
                      [120,160,100,180,110,80]] ).T