1 files changed, 53 insertions, 0 deletions
diff --git a/AK/Error.h b/AK/Error.h
new file mode 100644
index 0000000000..b91721920d
--- /dev/null
+++ b/AK/Error.h
@@ -0,0 +1,53 @@
+#pragma once
+
+#include <AK/Platform.h>
+
+namespace AK {
+
+template <typename T, auto NoErrorValue>
+class CONSUMABLE(unknown) Error {
+public:
+    RETURN_TYPESTATE(unknown)
+    Error()
+        : t(NoErrorValue)
+    {}
+
+    RETURN_TYPESTATE(unknown)
+    Error(T t)
+        : t(t)
+    {}
+
+    RETURN_TYPESTATE(unknown)
+    Error(Error&& other)
+        : t(move(other.t))
+    {
+    }
+
+    RETURN_TYPESTATE(unknown)
+    Error(const Error& other)
+        : t(other.t)
+    {
+    }
+
+    CALLABLE_WHEN("unknown", "consumed")
+    ~Error() {}
+
+    SET_TYPESTATE(consumed)
+    bool failed() const {
+        return t != NoErrorValue;
+    }
+
+    [[deprecated]]
+    SET_TYPESTATE(consumed)
+    void ignore() {}
+
+    const T& value() const { return t; }
+
+    bool operator==(const Error& o) { return t == o.t; }
+    bool operator!=(const Error& o) { return t != o.t; }
+    T t;
+};
+
+}
+
+using AK::Error;