From f7a161c69030ea18f352dd5fd37cf1ae4ea4d040 Mon Sep 17 00:00:00 2001
From: Deukhoofd <Deukhoofd@gmail.com>
Date: Fri, 11 Dec 2020 16:02:18 +0100
Subject: [PATCH] Adds new result class to show a functions success or failure.

---
 src/Result.hpp | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 src/Result.hpp

diff --git a/src/Result.hpp b/src/Result.hpp
new file mode 100644
index 0000000..cad2b62
--- /dev/null
+++ b/src/Result.hpp
@@ -0,0 +1,58 @@
+#ifndef ARBUTILS_RESULT_HPP
+#define ARBUTILS_RESULT_HPP
+
+namespace ArbUt {
+    /// @brief Whether the result was okay, or was an error
+    enum class ResultStatus : uint8_t { Ok, Error };
+
+    /// @brief Simple data class to return a functions success or failure.
+    /// @tparam T The potential return value of the function.
+    template <class T> class Result<T> {
+    public:
+        /// @brief Return a success, along with the success value.
+        /// @param value The value to return.
+        /// @return The result class
+        inline static const Result& Ok(T value) { return Result(ResultStatus::Ok, value); }
+        /// @brief Return an error, along with an error message.
+        /// @param message The error message to return
+        /// @return The result class
+        inline static const Result& Error(const std::string& message) { return Result(message); }
+
+        /// @brief Returns whether or not the function succeeded,
+        /// @return Whether or not the function succeeded.
+        [[nodiscard]] inline ResultStatus GetStatus() const noexcept { return _resultStatus; }
+
+        /// @brief The value of the result if it was successful.
+        /// @return The value of the result if it was successful.
+        inline const T& GetValue() const noexcept {
+            Assert(_resultStatus == ResultStatus::Ok);
+            return _resultValue;
+        }
+
+        /// @brief The value of the result if it was successful.
+        /// @return The value of the result if it was successful.
+        inline T& GetValue() noexcept {
+            Assert(_resultStatus == ResultStatus::Ok);
+            return _resultValue;
+        }
+
+        /// @brief Returns the error message if it errored.
+        /// @return The error message if it errored.
+        [[nodiscard]] inline const std::string& GetErrorMessage() const noexcept {
+            Assert(_resultStatus == ResultStatus::Error);
+            return _errorMessage;
+        }
+
+    private:
+        Result(ResultStatus result, const T& value) : _resultStatus(result), _resultValue(value) {}
+        explicit Result(const std::string& error) : _resultStatus(ResultStatus::Error), _errorMessage(error) {}
+
+        ResultStatus _resultStatus;
+        union {
+            T _resultValue;
+            std::string _errorMessage{};
+        };
+    };
+}
+
+#endif // ARBUTILS_RESULT_HPP