feat(example): validated_type and ranged_representation example types added

example/CMakeLists.txt

@@ -22,6 +22,9 @@
 
 cmake_minimum_required(VERSION 3.2)
 
+add_library(example_utils INTERFACE)
+target_include_directories(example_utils INTERFACE include)
+
 #
 # add_example(target <depependencies>...)
 #

example/include/ranged_representation.h

@@ -0,0 +1,52 @@
+// The MIT License (MIT)
+//
+// Copyright (c) 2018 Mateusz Pusz
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+#pragma once
+
+#include "validated_type.h"
+#include <algorithm>
+#include <type_traits>
+
+template<auto Min, auto Max>
+inline constexpr auto is_in_range = [](const auto& v) { return std::clamp(v, Min, Max) == v; };
+
+template<typename T, T Min, T Max>
+class ranged_representation : public validated_type<T, decltype(is_in_range<Min, Max>)> {
+public:
+  using base = validated_type<T, decltype(is_in_range<Min, Max>)>;
+  using base::validated_type;
+  constexpr ranged_representation() : base(T{}) {}
+
+  [[nodiscard]] constexpr ranged_representation operator-() const { return ranged_representation(-this->value()); }
+};
+
+template<typename T, T Min, T Max>
+struct std::common_type<std::intmax_t, ranged_representation<T, Min, Max>> :
+    std::type_identity<
+      ranged_representation<std::common_type_t<std::intmax_t, T>, std::common_type_t<std::intmax_t, T>{Min},
+                            std::common_type_t<std::intmax_t, T>{Max}>> {};
+
+template<typename T, T Min, T Max>
+struct std::common_type<ranged_representation<T, Min, Max>, std::intmax_t> :
+    std::type_identity<
+      ranged_representation<std::common_type_t<T, std::intmax_t>, std::common_type_t<T, std::intmax_t>{Min},
+                            std::common_type_t<T, std::intmax_t>{Max}>> {};

example/include/validated_type.h

@@ -0,0 +1,81 @@
+// The MIT License (MIT)
+//
+// Copyright (c) 2018 Mateusz Pusz
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+#pragma once
+
+#include <gsl/gsl-lite.hpp>
+#include <units/bits/external/hacks.h>
+#include <utility>
+
+inline constexpr struct validated_tag {
+} validated;
+
+template<std::movable T, std::predicate<T> Validator>
+class validated_type {
+  T value_;
+public:
+  using value_type = T;
+
+  static constexpr bool validate(const T& value) { return Validator()(value); }
+
+  constexpr explicit validated_type(const T& value) noexcept(std::is_nothrow_copy_constructible_v<T>)
+    requires std::copyable<T>
+  : value_(value)
+  {
+    gsl_Expects(validate(value_));
+  }
+
+  constexpr explicit validated_type(T&& value) noexcept(std::is_nothrow_move_constructible_v<T>) :
+      value_(std::move(value))
+  {
+    gsl_Expects(validate(value_));
+  }
+
+  constexpr validated_type(const T& value, validated_tag) noexcept(std::is_nothrow_copy_constructible_v<T>)
+    requires std::copyable<T>
+  : value_(value)
+  {
+  }
+
+  constexpr validated_type(T&& value, validated_tag) noexcept(std::is_nothrow_move_constructible_v<T>) :
+      value_(std::move(value))
+  {
+  }
+
+  constexpr explicit(false) operator T() const noexcept(std::is_nothrow_copy_constructible_v<T>)
+    requires std::copyable<T>
+  {
+    return value_;
+  }
+
+  constexpr T& value() & noexcept = delete;
+  constexpr const T& value() const& noexcept { return value_; }
+  constexpr T&& value() && noexcept { return std::move(value_); }
+  constexpr const T&& value() const&& noexcept { return std::move(value_); }
+
+  bool operator==(const validated_type&) const
+    requires std::equality_comparable<T>
+  = default;
+  auto operator<=>(const validated_type&) const
+    requires std::three_way_comparable<T>
+  = default;
+};