simply::collections

A small C++ library for implementing collections suitable for use in high-level object-oriented APIs. The C++ iterators are a chore to implement and represent collections with a low-level, pointer-like abstraction. The proposed C++ range concept is much closer to what is needed in modern APIs. This library is a separate implementation of this concept focused on API readability and ease of implementation.

use

Add the simply.collections NuGet package to your Visual C++ project using the Package Manager Dialog or the Package Manager Console.

Install-Package simply.collections

Include the library header and use its namespace.

#include <simply/collections.h>
using namespace simply;

Implement an enumerable, an internal class encapsulating a collection and responsible for creating enumerators.

#using <memory>

class answer_enumerable : public enumerable<int>
{
    std::vector<int> answers { 40, 41, 42 };
public:
    std::unique_ptr<enumerator<int>> create_enumerator() override
    {
        return std::make_unique<answer_enumerator>(answers);
    }
};

Implement an enumerator, an internal class responsible for returning elements of the collection, one by one.

#using <vector>

class answer_enumerator : public enumerator<int>
{
    const std::vector<int> answers;
    size_t index = 0;
public:
    answer_enumerator(const std::vector<int> answers) : answers(answers)
    {
    }

    bool get_next(int* element) override
    {
        if (index < answers.size())
        {
            *element = answers[index++];
            return true;
        }

        return false;
    }
};

Use the range class to expose the collection in your API. Internally, it relies on the enumerable and enumerator to implement begin and end iterators.

#using <memory>

class question
{
public:
    range<int> answers()
    {
        return range<int> { std::make_shared<answer_enumerable>() };
    }
};

You can use range with the C++ 11 for loop, the STL algorithms or any other code expecting C++ iterators.

#include <iostream>
#include <algorithm>

question q;
range<int> answers { q.answers() };

for (int answer : answers)
    std::cout << answer;

std::for_each(std::begin(answers), std::end(answers), [](int answer) {
    std::cout << answer;
});

clone

This repository contains submodules.

git clone --recursive https://github.com/olegsych/simply.collections.git

build

From Visual Studio 2017:

• Open simply.collections.sln
• Select Build Solution from the Build menu
• To switch build between x86 and x64 platforms, select Configuration Manager from the Build menu and change the Active Solution Configuration

From Developer Command Prompt for VS2017:

msbuild simply.collections.sln /p:Platform=x86
msbuild simply.collections.sln /p:Platform=x64

test

From Visual Studio 2017:

• Select Run / All Tests from the Test menu
• To switch test execution between x86 and x64 platform, select Test Settings from the Test menu and change the Default Processor Architecture.

From Developer Command Prompt for VS2017:

vstest.console bin\Win32\test.dll /Platform:x86
vstest.console bin\x64\test.dll /Platform:x64 /inIsolation