draconisplusplus/include/rfl/Rename.hpp

#ifndef RFL_RENAME_HPP_
#define RFL_RENAME_HPP_

#include <algorithm>
#include <string_view>
#include <tuple>
#include <type_traits>
#include <utility>

#include "Literal.hpp"
#include "default.hpp"
#include "internal/StringLiteral.hpp"

namespace rfl {

  /// Used to assign a new name to a field, which is different from the name
  /// inside the struct.
  template <internal::StringLiteral _name, class T>
  struct Rename {
    /// The underlying type.
    using Type = T;

    /// The name of the field.
    using Name = rfl::Literal<_name>;

    Rename() : value_(Type()) {}

    Rename(const Type& _value) : value_(_value) {}

    Rename(Type&& _value) noexcept : value_(std::move(_value)) {}

    Rename(Rename<_name, T>&& _field) noexcept = default;

    Rename(const Rename<_name, Type>& _field) = default;

    template <class U>
    Rename(const Rename<_name, U>& _field) : value_(_field.get()) {}

    template <class U>
    Rename(Rename<_name, U>&& _field) : value_(_field.get()) {}

    template <
        class U,
        typename std::enable_if<std::is_convertible_v<U, Type>, bool>::type =
            true>
    Rename(const U& _value) : value_(_value) {}

    template <
        class U,
        typename std::enable_if<std::is_convertible_v<U, Type>, bool>::type =
            true>
    Rename(U&& _value) noexcept : value_(std::forward<U>(_value)) {}

    template <
        class U,
        typename std::enable_if<std::is_convertible_v<U, Type>, bool>::type =
            true>
    Rename(const Rename<_name, U>& _field) : value_(_field.value()) {}

    /// Assigns the underlying object to its default value.
    template <
        class U = Type,
        typename std::enable_if<std::is_default_constructible_v<U>, bool>::
            type = true>
    Rename(const Default& _default) : value_(Type()) {}

    ~Rename() = default;

    /// The name of the field, for internal use.
    constexpr static const internal::StringLiteral name_ = _name;

    /// Returns the underlying object.
    const Type& get() const { return value_; }

    /// Returns the underlying object.
    Type& operator()() { return value_; }

    /// Returns the underlying object.
    const Type& operator()() const { return value_; }

    /// Assigns the underlying object.
    auto& operator=(const Type& _value) {
      value_ = _value;
      return *this;
    }

    /// Assigns the underlying object.
    auto& operator=(Type&& _value) noexcept {
      value_ = std::move(_value);
      return *this;
    }

    /// Assigns the underlying object.
    template <
        class U,
        typename std::enable_if<std::is_convertible_v<U, Type>, bool>::type =
            true>
    auto& operator=(const U& _value) {
      value_ = _value;
      return *this;
    }

    /// Assigns the underlying object to its default value.
    template <
        class U = Type,
        typename std::enable_if<std::is_default_constructible_v<U>, bool>::
            type = true>
    auto& operator=(const Default& _default) {
      value_ = Type();
      return *this;
    }

    /// Assigns the underlying object.
    Rename<_name, T>& operator=(const Rename<_name, T>& _field) = default;

    /// Assigns the underlying object.
    Rename<_name, T>& operator=(Rename<_name, T>&& _field) = default;

    /// Assigns the underlying object.
    template <class U>
    auto& operator=(const Rename<_name, U>& _field) {
      value_ = _field.get();
      return *this;
    }

    /// Assigns the underlying object.
    template <class U>
    auto& operator=(Rename<_name, U>&& _field) {
      value_ = std::forward<T>(_field.value_);
      return *this;
    }

    /// Assigns the underlying object.
    void set(const Type& _value) { value_ = _value; }

    /// Assigns the underlying object.
    void set(Type&& _value) { value_ = std::move(_value); }

    /// Returns the underlying object.
    Type& value() { return value_; }

    /// Returns the underlying object.
    const Type& value() const { return value_; }

    /// The underlying value.
    Type value_;
  };

} // namespace rfl

#endif