Compilation error while trying to compile AWS-SDK-CPP s3 example code

Question

I am trying to use AWS C++ SDK to upload file to s3. However it seems that the existing example does not work. Following is my sample code:

invocation_response putFileObject(S3::S3Client &client, const String& bucketName, const String& objectName) {
    const string fileName = "/tmp/test";
    auto inputData =
            Aws::MakeShared<Aws::FStream>("SampleAllocationTag",
                                          fileName.c_str(),
                                          std::ios_base::in | std::ios_base::binary);
    S3::Model::PutObjectRequest request;
    request.SetBucket(bucketName);
    request.SetKey(objectName);
    request.SetBody(inputData);

    S3::Model::PutObjectOutcome outcome =
        client.PutObject(request);
    if (!outcome.IsSuccess()) {
        cout << "Failure Putting Object" << endl;
        return invocation_response::failure("Error Putobject", "application/json");

    }
    else {
        cout << "Success Putting Object" << endl;
        return invocation_response::success("Success Putobject", "application/json");

    }
} 

I run into the following compilation error:

In function ‘aws::lambda_runtime::invocation_response putFileObject(Aws::S3::S3Client&, const String&, const String&)’: error: cannot convert ‘std::shared_ptrstd::basic_fstream<char >’ to ‘const std::shared_ptrstd::basic_iostream<char >&’

I am sure I am missing something straightforward. Any help would be appreciated.

Tried changing the FStream to OStream and still that did no work