From 8db26a7350aad53ed73a127f9b8eb6ef15bf0be1 Mon Sep 17 00:00:00 2001
From: Steven Le Rouzic <steven.lerouzic@gmail.com>
Date: Thu, 11 Apr 2024 23:49:22 +0200
Subject: Implement Status

---
 deimos/core/status.h | 111 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 111 insertions(+)
 create mode 100644 deimos/core/status.h

(limited to 'deimos/core/status.h')

diff --git a/deimos/core/status.h b/deimos/core/status.h
new file mode 100644
index 0000000..f866182
--- /dev/null
+++ b/deimos/core/status.h
@@ -0,0 +1,111 @@
+#pragma once
+
+#include "deimos/core/base.h"
+
+namespace deimos
+{
+
+enum class StatusCode : uint32_t
+{
+    kOk = 0,
+    kUnknown,
+    kInvalidArgument,
+    kUnimplemented,
+    kInternal,
+};
+
+struct StatusRep
+{
+    // @Todo Make this atomic
+    int32_t                     ref_count{};
+    StatusCode                  code{};
+    StringView                  message;
+};
+
+class Status
+{
+    uintptr_t m_rep;
+
+    constexpr bool IsInline() const
+    {
+        return (m_rep & 1U) == 1U;
+    }
+
+    static constexpr uintptr_t CodeToRep(StatusCode code)
+    {
+        return ((uint32_t)code << 1U) | 1U;
+    }
+
+    void Ref() const;
+    void Unref() const;
+
+public:
+    constexpr Status() : Status(StatusCode::kOk) {}
+    constexpr explicit Status(StatusCode code) : m_rep{CodeToRep(code)} {}
+    Status(StatusCode code, StringView message);
+
+    Status(const Status& other) : m_rep{other.m_rep}
+    {
+        Ref();
+    }
+
+    Status(Status&& other) : m_rep{std::exchange(other.m_rep, 0U)} {}
+
+    Status& operator=(const Status& other)
+    {
+        if (this != &other)
+        {
+            Unref();
+            this->m_rep = other.m_rep;
+            Ref();
+        }
+        return *this;
+    }
+
+    Status& operator=(Status&& other)
+    {
+        if (this != &other)
+        {
+            Unref();
+            this->m_rep = std::exchange(other.m_rep, 0U);
+
+        }
+        return *this;
+    }
+
+    ~Status()
+    {
+        Unref();
+    }
+
+    constexpr bool ok() const { return m_rep == CodeToRep(StatusCode::kOk); }
+
+    StatusCode code() const
+    {
+        if (IsInline()) { return (StatusCode)(m_rep >> 1U); }
+        return std::bit_cast<StatusRep*>(m_rep)->code;
+    }
+};
+
+inline Status UnknownError(StringView message = {})
+{
+    return Status(StatusCode::kUnknown, message);
+}
+
+inline Status InvalidArgumentError(StringView message = {})
+{
+    return Status(StatusCode::kInvalidArgument, message);
+}
+
+inline Status UnimplementedError(StringView message = {})
+{
+    return Status(StatusCode::kUnimplemented, message);
+}
+
+inline Status InternalError(StringView message = {})
+{
+    return Status(StatusCode::kInternal, message);
+}
+
+} // namespace deimos
+
-- 
cgit