CppPlay

Introduction

This repository contains some of my codes to explore C++.

Modules

1. Functional Programming with C++

#include "functional.hpp"

int add1(int k) { return k + 1; }

int mul2(int k) { return k * 2; }

int sub3(int k) { return k - 3; }

// 1
FP::Run(3, &add1, &mul2, &add1, &sub3); // (3+1)*2+1-3 = 6 

// 2
FP::Pipeline<int> math;
math.Register(&add1).Register(&mul2).Register(&add1).Register(&sub3);
math(3); // 6

2. A Generic Matrix Class to Learn Metaprogramming

#include "matrix.hpp"

nMatrix<int, 2, 3> mx1{1, 2, 3, 0, 5, 1};
nMatrix<int, 2, 3> mx2{2, 2, 2, 2, 2, 2} ;

auto mx3 = mx1 + mx2;
mx3(0, 0); // (2 + 1) == 3
mx3(1, 1); // (2 + 5) == 7

3. Mimic Go Channel

#include "channel.hpp"
#include <iostream>
#include <vector>

using namespace std;

int main() {
    Channel<int> chan(10);
    int numConsumer = 1;
    int numData = 1000;
    int *input = new int[numData];
    int *output = new int[numData];
    for (int i = 0; i < numData; i++) {
        input[i] = i;
    }
    vector<thread> consumers(numConsumer);
    /* start consumers first */
    for (int i = 0; i < numConsumer; ++i) {
        consumers[i] = thread{[&]() {
            int k;
            while (chan >> k) {
                output[k] = k;
            }
        }};
    }
    /* then begin producing */
    for (int i = 0; i < numData; ++i) {
        chan << input[i];
    }
    /* when data is done, close the channel */
    chan.Close();
    /* wait until consumer is done */
    for (auto& t: consumers) {
        if (t.joinable()) t.join();
    }
    /* show data */
    for (int i = 0; i < numData; ++i) {
        cerr << output[i] << endl;
    }
    delete[] input;
    delete[] output;
}