Code:

// ...int maxSerializeBufferSize = 1024*1024*5;btDefaultSerializer Serializer(maxSerializeBufferSize);Serializer.startSerialization();if(m_pCollisionShape)     m_pCollisionShape->serializeSingleShape(&Serializer);else{     btBoxShape BoxShape(btVector3(2,2,2));     BoxShape.serializeSingleShape(&Serializer);}Serializer.finishSerialization();FileOut.CollisionShapeDataSize = Serializer.getCurrentBufferSize();std::ofstream Stream(GetFilename());Stream.write((char*)&FileOut, sizeof(File));Stream.write((char*)Serializer.getBufferPointer(), FileOut.CollisionShapeDataSize);

Code:

// ...char* pCollisionShapeData = new char[FileIn.CollisionShapeDataSize];Stream.read(pCollisionShapeData, FileIn.CollisionShapeDataSize);btBulletWorldImporter Importer(0);if(Importer.loadFileFromMemory(pCollisionShapeData, FileIn.CollisionShapeDataSize) && Importer.getNumCollisionShapes()){    btCollisionShape* pShape = Importer.getCollisionShapeByIndex(0);    if(pShape->getShapeType() == BOX_SHAPE_PROXYTYPE)        m_pCollisionShape = new btBoxShape(*static_cast<btBoxShape*>(pShape));    else if(pShape->getShapeType() == TRIANGLE_MESH_SHAPE_PROXYTYPE)        m_pCollisionShape = new btBvhTriangleMeshShape(*static_cast<btBvhTriangleMeshShape*>(pShape));}else{    // ...}delete[] pCollisionShapeData;