Add Clone() function to Error class

mogemimi · Dec 15, 2020 · 0f8be09 · 0f8be09
1 parent e656f12
commit 0f8be09
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Showing 2 changed files with 39 additions and 8 deletions.
diff --git a/include/Pomdog/Utility/Errors.hpp b/include/Pomdog/Utility/Errors.hpp
@@ -14,7 +14,11 @@ class POMDOG_EXPORT Error {
 public:
     virtual ~Error() noexcept = default;
 
+    /// Returns a string representation of the error.
     [[nodiscard]] virtual std::string ToString() const noexcept = 0;
+
+    /// Creates a new object that is a copy of the error.
+    [[nodiscard]] virtual std::unique_ptr<Error> Clone() const noexcept = 0;
 };
 
 } // namespace Pomdog
@@ -26,23 +30,27 @@ class POMDOG_EXPORT IOError final : public Error {
     std::errc Kind;
     std::string Reason;
 
+    /// Returns a string representation of the error.
     [[nodiscard]] std::string ToString() const noexcept;
+
+    /// Creates a new object that is a copy of the error.
+    [[nodiscard]] std::unique_ptr<Error> Clone() const noexcept;
 };
 
 [[nodiscard]] POMDOG_EXPORT
 std::shared_ptr<IOError>
-New(std::errc kind, std::string&& reason);
+New(std::errc kind, std::string&& reason) noexcept;
 
 [[nodiscard]] POMDOG_EXPORT
 std::shared_ptr<Error>
-New(std::string&& message);
+New(std::string&& message) noexcept;
 
 [[nodiscard]] POMDOG_EXPORT
 std::shared_ptr<Error>
-Wrap(const std::shared_ptr<Error>& err, std::string&& message);
+Wrap(const std::shared_ptr<Error>& err, std::string&& message) noexcept;
 
 [[nodiscard]] POMDOG_EXPORT
 std::shared_ptr<Error>
-Wrap(std::shared_ptr<Error>&& err, std::string&& message);
+Wrap(std::shared_ptr<Error>&& err, std::string&& message) noexcept;
 
 } // namespace Pomdog::Errors
diff --git a/src/Utility/Errors.cpp b/src/Utility/Errors.cpp
@@ -15,6 +15,13 @@ class StringError final : public Error {
     {
         return this->Message;
     }
+
+    [[nodiscard]] std::unique_ptr<Error> Clone() const noexcept
+    {
+        auto err = std::make_unique<StringError>();
+        err->Message = this->Message;
+        return err;
+    }
 };
 
 class WrappedError final : public Error {
@@ -29,37 +36,53 @@ class WrappedError final : public Error {
         }
         return this->Message;
     }
+
+    [[nodiscard]] std::unique_ptr<Error> Clone() const noexcept
+    {
+        auto err = std::make_unique<WrappedError>();
+        err->Err = this->Err->Clone();
+        err->Message = this->Message;
+        return err;
+    }
 };
 
 std::string IOError::ToString() const noexcept
 {
     return this->Reason + ": " + std::make_error_code(this->Kind).message();
 }
 
-std::shared_ptr<IOError> New(std::errc kind, std::string&& reason)
+std::unique_ptr<Error> IOError::Clone() const noexcept
+{
+    auto err = std::make_unique<IOError>();
+    err->Kind = this->Kind;
+    err->Reason = this->Reason;
+    return err;
+}
+
+std::shared_ptr<IOError> New(std::errc kind, std::string&& reason) noexcept
 {
     auto err = std::make_shared<IOError>();
     err->Kind = kind;
     err->Reason = std::move(reason);
     return err;
 }
 
-std::shared_ptr<Error> New(std::string&& message)
+std::shared_ptr<Error> New(std::string&& message) noexcept
 {
     auto err = std::make_shared<StringError>();
     err->Message = std::move(message);
     return std::move(err);
 }
 
-std::shared_ptr<Error> Wrap(const std::shared_ptr<Error>& err, std::string&& message)
+std::shared_ptr<Error> Wrap(const std::shared_ptr<Error>& err, std::string&& message) noexcept
 {
     auto wrapped = std::make_shared<WrappedError>();
     wrapped->Err = err;
     wrapped->Message = std::move(message);
     return std::move(wrapped);
 }
 
-std::shared_ptr<Error> Wrap(std::shared_ptr<Error>&& err, std::string&& message)
+std::shared_ptr<Error> Wrap(std::shared_ptr<Error>&& err, std::string&& message) noexcept
 {
     auto wrapped = std::make_shared<WrappedError>();
     wrapped->Err = std::move(err);