Cannot link InMemoryRandomAccessStream

Question

I have a C++ class that utilizes winrt::Windows::Storage::Streams::InMemoryRandomAccessStream. This class will compile, but it will not link... I get the following error:

LNK2019 unresolved external symbol "public: __cdecl winrt::Windows::Storage::Streams::InMemoryRandomAccessStream::InMemoryRandomAccessStream(void)"

I have tried to complie this code with the following variations all with the same linker error:

• different versions of the Windows SDK.
• different versions of the C++ compiler (17 & 20) always with the same result.

I have reduced this class down to the following:

Microphone.h

#pragma once
#include <windows.h>
#include <winrt/Windows.Foundation.h>
#include <winrt/Windows.Foundation.Collections.h>
#include <winrt/Windows.ApplicationModel.Core.h>
#include <winrt/Windows.UI.Core.h>
#include <winrt/Windows.UI.Composition.h>
#include <winrt/Windows.UI.Input.h>
#include <winrt/Windows.Foundation.h>
#include <winrt/Windows.Media.Capture.h>
#include <winrt/Windows.Media.MediaProperties.h>
using namespace winrt::Windows::Media::Capture;
using namespace winrt::Windows::Media::MediaProperties;
class Microphone
{
public:
    Microphone();
    void StartRecording();
    void StopRecording();
    winrt::Windows::Storage::Streams::InMemoryRandomAccessStream AudioStream();
private:
    MediaCapture mediaCapture;
    winrt::Windows::Storage::Streams::InMemoryRandomAccessStream audioStream;
};

Microphone.cpp

#include "Microphone.h"

Microphone::Microphone()
{
    // Initialize the MediaCapture object
    mediaCapture = MediaCapture();
    auto settings = MediaCaptureInitializationSettings();
    settings.StreamingCaptureMode(StreamingCaptureMode::Audio);
    mediaCapture.InitializeAsync(settings).get();
}
void Microphone::StartRecording()
{
    // Set up the audio encoding properties
    auto audioProfile = MediaEncodingProfile::CreateWav(AudioEncodingQuality::High);
    // Start recording audio
    mediaCapture.StartRecordToStreamAsync(audioProfile, audioStream).get();
}
void Microphone::StopRecording()
{
    // Stop recording audio
    mediaCapture.StopRecordAsync().get();
}
winrt::Windows::Storage::Streams::InMemoryRandomAccessStream Microphone::AudioStream()
{
    return audioStream;
}

MicMain.cpp

#include <winrt/Windows.Storage.Streams.h>
#include <winrt/base.h>
#include <thread>
#include <iostream>
#include <future>

#include "Microphone.h"

using namespace winrt;
using namespace Windows::Storage::Streams;
using namespace Windows::Foundation;
void DumpStreamToConsol(InMemoryRandomAccessStream stream)
{
    auto size = stream.Size();
    if (size > std::numeric_limits<uint32_t>::max())
    {
        return;
    }
    auto reader = DataReader(stream.GetInputStreamAt(0));
    reader.LoadAsync(static_cast<uint32_t>(size)).get();
    for (uint32_t i = 0; i < size; ++i)
    {
        uint8_t byte = reader.ReadByte();
        std::cout << byte;
    }
}

int main(int argc, char* argv[])
{
    winrt::init_apartment();
    // Print out the command line arguments
    for (int i = 0; i < argc; ++i) {
        std::cout << "Argument " << i << ": " << argv[i] << std::endl;
    }

    // Your code here
    Microphone mic;
    // capture 5 seconds of audio
    mic.StartRecording();
    std::this_thread::sleep_for(std::chrono::seconds(5));
    mic.StopRecording();

    auto stream = mic.AudioStream();
    DumpStreamToConsol(stream);

    return 0;
}```