applied platformio structure

lib/spotify/cspot/bell/main/io/include/StreamUtils.h

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <cstddef>
+#include <istream>
+#include <streambuf>
+
+namespace bell {
+struct MemoryBuffer : std::streambuf {
+  MemoryBuffer(std::byte const* base, size_t size) {
+    std::byte* p(const_cast<std::byte*>(base));
+    this->setg((char*)p, (char*)p, (char*)p + size);
+  }
+};
+struct IMemoryStream : virtual MemoryBuffer, std::istream {
+  IMemoryStream(std::byte const* base, size_t size)
+      : MemoryBuffer(base, size),
+        std::istream(static_cast<std::streambuf*>(this)) {}
+};
+}  // namespace bell