wanda: restructure source directory

1 files changed, 256 insertions, 0 deletions

diff --git a/source/include/wanda/expected.hpp b/source/include/wanda/expected.hpp
new file mode 100644
index 0000000..fff0d81
--- /dev/null
+++ b/source/include/wanda/expected.hpp
@@ -0,0 +1,256 @@
+/**
+ * @file   expected.hpp
+ * @author Felix Morgner (felix.morgner@gmail.com)
+ * @since  1.0.0
+ */
+
+#ifndef WANDA_EXPECTED_HPP
+#define WANDA_EXPECTED_HPP
+
+#include <initializer_list>
+#include <type_traits>
+#include <utility>
+
+namespace wanda
+{
+  /**
+    * @brief A type to represent the error case of a computation based on #wanda::expected
+    */
+  template<typename ErrorType>
+  struct unexpected
+  {
+    static_assert(!std::is_same_v<ErrorType, void>, "ErrorType can not be 'void'!");
+    static_assert(!std::is_array_v<ErrorType>, "ErrorType can not be an array type!");
+
+    /**
+     * @brief Copy construct a new @p unexpected from another @p unexpected
+     */
+    constexpr unexpected(unexpected const &) = default;
+
+    /**
+     * @brief Move construct a new @p unexpected from another @p unexpected
+     */
+    constexpr unexpected(unexpected &&) = default;
+
+    /**
+     * @brief Construct a new @p unexpected by direct initializing the error object from @p args
+     */
+    template<typename... Args>
+    constexpr explicit unexpected(std::in_place_t, Args &&... args)
+        : m_error(std::forward<Args>(args)...)
+    {
+    }
+
+    /**
+     * @brief Construct a new @p unexpected by direct initializing the error object from @p il and @p args
+     */
+    template<
+        typename U,
+        typename... Args,
+        std::enable_if_t<std::is_constructible_v<ErrorType, std::initializer_list<U>, Args...>> * = nullptr>
+    constexpr explicit unexpected(std::in_place_t, std::initializer_list<U> il, Args &&... args)
+        : m_error(il, std::forward<Args>(args)...)
+    {
+    }
+
+    /**
+     * @brief Construct a new @p unexpected by direct initializing the error object from @p error
+     */
+    template<
+        typename Err = ErrorType,
+        std::enable_if_t<std::is_constructible_v<ErrorType, Err> &&
+                         !std::is_same_v<std::remove_cv_t<std::remove_reference_t<Err>>, std::in_place_t> &&
+                         !std::is_same_v<std::remove_cv_t<std::remove_reference_t<Err>>, unexpected>> * = nullptr>
+    constexpr explicit unexpected(Err && error)
+        : m_error(std::forward<Err>(error))
+    {
+    }
+
+    /**
+     * @brief Construct a new @p unexpected by copying the value of another @p unexpected of different error type
+     */
+    template<
+        typename Err,
+        std::enable_if_t<!(
+            std::is_constructible_v<ErrorType, Err> &&
+            !std::is_constructible_v<ErrorType, unexpected<Err> &> &&
+            !std::is_constructible_v<ErrorType, unexpected<Err>> &&
+            !std::is_constructible_v<ErrorType, unexpected<Err> const &> &&
+            !std::is_constructible_v<ErrorType, unexpected<Err> const> &&
+            !std::is_convertible_v<unexpected<Err> &, ErrorType> &&
+            !std::is_convertible_v<unexpected<Err>, ErrorType> &&
+            !std::is_convertible_v<unexpected<Err> const &, ErrorType> &&
+            !std::is_convertible_v<unexpected<Err> const, ErrorType>)> * = nullptr,
+        std::enable_if_t<!std::is_convertible_v<Err, ErrorType>> * = nullptr>
+    constexpr explicit unexpected(unexpected<Err> const & error)
+        : m_error(error.m_error)
+    {
+    }
+
+    /**
+     * @brief Construct a new @p unexpected by copying the value of another @p unexpected of different error type
+     */
+    template<
+        typename Err,
+        std::enable_if_t<!(
+            std::is_constructible_v<ErrorType, Err> &&
+            !std::is_constructible_v<ErrorType, unexpected<Err> &> &&
+            !std::is_constructible_v<ErrorType, unexpected<Err>> &&
+            !std::is_constructible_v<ErrorType, unexpected<Err> const &> &&
+            !std::is_constructible_v<ErrorType, unexpected<Err> const> &&
+            !std::is_convertible_v<unexpected<Err> &, ErrorType> &&
+            !std::is_convertible_v<unexpected<Err>, ErrorType> &&
+            !std::is_convertible_v<unexpected<Err> const &, ErrorType> &&
+            !std::is_convertible_v<unexpected<Err> const, ErrorType>)> * = nullptr,
+        std::enable_if_t<std::is_convertible_v<Err, ErrorType>> * = nullptr>
+    constexpr unexpected(unexpected<Err> const & error)
+        : m_error(error.m_error)
+    {
+    }
+
+    /**
+     * @brief Construct a new @p unexpected by moving the value of another @p unexpected of different error type
+     */
+    template<
+        typename Err,
+        std::enable_if_t<!(
+            std::is_constructible_v<ErrorType, Err> &&
+            !std::is_constructible_v<ErrorType, unexpected<Err> &> &&
+            !std::is_constructible_v<ErrorType, unexpected<Err>> &&
+            !std::is_constructible_v<ErrorType, unexpected<Err> const &> &&
+            !std::is_constructible_v<ErrorType, unexpected<Err> const> &&
+            !std::is_convertible_v<unexpected<Err> &, ErrorType> &&
+            !std::is_convertible_v<unexpected<Err>, ErrorType> &&
+            !std::is_convertible_v<unexpected<Err> const &, ErrorType> &&
+            !std::is_convertible_v<unexpected<Err> const, ErrorType>)> * = nullptr,
+        std::enable_if_t<!std::is_convertible_v<Err, ErrorType>> * = nullptr>
+    constexpr explicit unexpected(unexpected<Err> && error)
+        : m_error(std::move(error.m_error))
+    {
+    }
+
+    /**
+     * @brief Construct a new @p unexpected by moving the value of another @p unexpected of different error type
+     */
+    template<
+        typename Err,
+        std::enable_if_t<!(
+            std::is_constructible_v<ErrorType, Err> &&
+            !std::is_constructible_v<ErrorType, unexpected<Err> &> &&
+            !std::is_constructible_v<ErrorType, unexpected<Err>> &&
+            !std::is_constructible_v<ErrorType, unexpected<Err> const &> &&
+            !std::is_constructible_v<ErrorType, unexpected<Err> const> &&
+            !std::is_convertible_v<unexpected<Err> &, ErrorType> &&
+            !std::is_convertible_v<unexpected<Err>, ErrorType> &&
+            !std::is_convertible_v<unexpected<Err> const &, ErrorType> &&
+            !std::is_convertible_v<unexpected<Err> const, ErrorType>)> * = nullptr,
+        std::enable_if_t<std::is_convertible_v<Err, ErrorType>> * = nullptr>
+    constexpr unexpected(unexpected<Err> && error)
+        : m_error(std::move(error.m_error))
+    {
+    }
+
+    /**
+     * @brief Get the error value contained in this @p unexpected instance
+     */
+    constexpr ErrorType const & value() const &
+    {
+      return m_error;
+    }
+
+    /**
+     * @brief Get the error value contained in this @p unexpected instance
+     */
+    constexpr ErrorType & value() &
+    {
+      return m_error;
+    }
+
+    /**
+     * @brief Get the error value contained in this @p unexpected instance
+     */
+    constexpr ErrorType && value() &&
+    {
+      return std::move(m_error);
+    }
+
+    /**
+     * @brief Get the error value contained in this @p unexpected instance
+     */
+    constexpr ErrorType const && value() const &&
+    {
+      return std::move(m_error);
+    }
+
+    /**
+     * @brief Swap the error value of this @p unexpected instance with the one of @p other
+     */
+    void swap(unexpected & other) noexcept(std::is_nothrow_swappable_v<ErrorType>)
+    {
+      using std::swap;
+      swap(m_error, other.m_error);
+    }
+
+    template<typename ErrorType1, typename ErrorType2>
+    friend constexpr bool operator==(unexpected<ErrorType1> const & lhs, unexpected<ErrorType2> const & rhs);
+
+    template<typename ErrorType1, typename ErrorType2>
+    friend constexpr bool operator!=(unexpected<ErrorType1> const & lhs, unexpected<ErrorType2> const & rhs);
+
+    template<
+        typename Err,
+        std::enable_if_t<std::is_swappable_v<Err>> *>
+    friend void swap(unexpected<Err> & lhs, unexpected<Err> & rhs);
+
+  private:
+    ErrorType m_error;
+  };
+
+  template<typename ErrorType>
+  unexpected(ErrorType)->unexpected<ErrorType>;
+
+  /**
+ * @brief Compare two @p unexpected instances for equality
+ */
+  template<typename ErrorType1, typename ErrorType2>
+  constexpr bool operator==(unexpected<ErrorType1> const & lhs, unexpected<ErrorType2> const & rhs)
+  {
+    return lhs.m_error == rhs.m_error;
+  }
+
+  /**
+ * @brief Compare two @p unexpected instances for inequality
+ */
+  template<typename ErrorType1, typename ErrorType2>
+  constexpr bool operator!=(unexpected<ErrorType1> const & lhs, unexpected<ErrorType2> const & rhs)
+  {
+    return lhs.m_error != rhs.m_error;
+  }
+
+  /**
+ * @brief Swap the error values of two @p unexpected instances
+ */
+  template<
+      typename Err,
+      std::enable_if_t<std::is_swappable_v<Err>> * = nullptr>
+  void swap(unexpected<Err> & lhs, unexpected<Err> & rhs)
+  {
+    lhs.swap(rhs);
+  }
+
+  /**
+ * @brief A tag type for @p unexpected
+ */
+  struct unexpect_t
+  {
+    explicit unexpect_t() = default;
+  };
+
+  /**
+ * @brief A tap for @p unexpected
+ */
+  inline constexpr unexpect_t unexpect{};
+
+}  // namespace wanda
+
+#endif
\ No newline at end of file