afio_hello_world.cpp

// Set a dispatcher as current for this thread
afio::current_dispatcher_guard h(afio::make_dispatcher().get());

// Config a write gather
std::vector<asio::const_buffer> buffers;
buffers.push_back(asio::const_buffer("He", 2));
buffers.push_back(asio::const_buffer("ll", 2));
buffers.push_back(asio::const_buffer("o ", 2));
buffers.push_back(asio::const_buffer("Wo", 2));
buffers.push_back(asio::const_buffer("rl", 2));
buffers.push_back(asio::const_buffer("d\n", 2));

// Will be initialized after file has been opened
handle file;

shared_future<std::vector<char> data_future =
    // Schedule an opening of a file called example_file.txt
    afio::async_file(
        "example_file.txt",
        afio::file_flags::create | afio::file_flags::read_write)
    .then(
        // Schedule truncate after file has been opened
        [&file](future<handle> fh)
        {
            file = fh.get();
            return afio::async_truncate(file, 12);
        }
    ).then(
        // Schedule the write gather to offset zero after the resize file
        [&file, &buffers](future<void> f)
        {
            // Possible error handling...
            f.get();

            return afio::async_write(file, buffers, 0);
        }
    ).then(
        // After everything has been written, sync
        [&file](future<void> f)
        {
            // Possible error handling...
            f.get();

            return afio::async_sync(file);
        }
    ).then(
        // Read the content after sync
        [&file](future<void> f)
        {
            return afio::async_read(file, 12, 0);
        }
    );

future<void> deleted = data_future.then(
    // Delete the file after we read from it.
    [&file](future<void> f)
    {
        // Possible error handling...
        f.get();

        return
            afio::async_close(file).then(
                [&file](future<void> f)
                {
                    // Possible error handling...
                    f.get();

                    return async::async_rmfile(file);
                }
            );
    }
);

std::vector<char> data = data_future.get();
std::string contents(buffer.begin(), buffer.end());
std::cout << "Contents of file is '" << contents << "'" << std::endl;

deleted.wait();
// Or if you care about possible errors, call .get() instead of wait().

// The same as above but with the help of the proposed coroutines functionality
handle file = await afio::async_file(
        "example_file.txt",
        afio::file_flags::create | afio::file_flags::read_write);

await afio::async_truncate(file, 12);
await afio::async_write(file, buffers, 0);
await afio::async_sync(file);
shared_future<std::vector<char>> data_future = afio::async_read(file, 12, 0);
future<void> deleted =
    data_future.then(
        [&file](future<void> f)
        {
            return afio::async_close(file).then(
                [&file](future<void> f){ return afio::async_rmfile(file); }
        }
    );

std::vector<char> data = data_future.get();
std::string contents(buffer.begin(), buffer.end());
std::cout << "Contents of file is '" << contents << "'" << std::endl;

await deleted;