public protocol SizedInBytes {
    associatedtype ByteStorage
}

@propertyWrapper
public struct Unaligned<Value: SizedInBytes> {
    private var storage: Value.ByteStorage

    public init(wrappedValue: Value) {
        precondition(MemoryLayout<Value.ByteStorage>.size == MemoryLayout<Value>.size, "byte storage has a different size")
        precondition(MemoryLayout<Value.ByteStorage>.alignment == 1, "byte storage must have byte alignment")
        self.storage = withUnsafeBytes(of: wrappedValue) {
            $0.load(as: Value.ByteStorage.self)
        }
    }

    public var wrappedValue: Value {
        get {
            // This allocation should get stack-promoted but doesn't.
            let result = UnsafeMutablePointer<Value>.allocate(capacity: 1)
            defer { result.deinitialize(count: 1); result.deallocate() }
            result.withMemoryRebound(to: Value.ByteStorage.self, capacity: 1) {
                $0.initialize(to: self.storage)
            }
            return result.pointee
        }
        set {
            self = .init(wrappedValue: newValue)
        }
    }
}

extension Int32: SizedInBytes {
    public typealias ByteStorage = (UInt8, UInt8, UInt8, UInt8)
}

public struct Test {
    @Unaligned public var x: Int32 = 0
}