Merge branch 'forwarding_ref'

Author: lefticus

CMakeLists.txt

@@ -6,7 +6,7 @@ cmake_minimum_required(VERSION 3.21)
 
 # Only set the cxx_standard if it is not set by someone else
 if (NOT DEFINED CMAKE_CXX_STANDARD)
-  set(CMAKE_CXX_STANDARD 20)
+  set(CMAKE_CXX_STANDARD 26)
 endif()
 
 # strongly encouraged to enable this globally to avoid conflicts between

include/lefticus/tools/forwarding_ref.hpp

@@ -0,0 +1,63 @@
+/*
+This is free and unencumbered software released into the public domain.
+
+Anyone is free to copy, modify, publish, use, compile, sell, or
+distribute this software, either in source code form or as a compiled
+binary, for any purpose, commercial or non-commercial, and by any
+means.
+
+In jurisdictions that recognize copyright laws, the author or authors
+of this software dedicate any and all copyright interest in the
+software to the public domain. We make this dedication for the benefit
+of the public at large and to the detriment of our heirs and
+successors. We intend this dedication to be an overt act of
+relinquishment in perpetuity of all present and future rights to this
+software under copyright law.
+
+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 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.
+
+For more information, please refer to <https://unlicense.org>
+*/
+
+
+#ifndef LEFTICUS_TOOLS_FORWARDING_REF_HPP
+#define LEFTICUS_TOOLS_FORWARDING_REF_HPP
+
+#include <type_traits>
+
+#include "lifetimebound.hpp"
+
+namespace lefticus::tools {
+
+template<typename T> struct [[nodiscard]] forwarding_ref
+{
+  using pointer_type = std::add_pointer_t<std::remove_reference_t<T>>;
+  using reference_type = T;
+
+  forwarding_ref(forwarding_ref &&) = delete (
+    "you accidentally moved a ref (auto obj = std::move(ref)) instead of (Type obj = ref)");
+  forwarding_ref(const forwarding_ref &) = delete (
+    "you accidentally copied a ref (auto obj = ref) instead of (Type obj = ref)");
+  forwarding_ref &operator=(forwarding_ref &&) = delete (
+    "you accidentally move assigned a ref (ref = std::move(other_ref))");
+  forwarding_ref &operator=(const forwarding_ref &) = delete ("you accidentally copy assigned a ref (ref = other_ref)");
+
+  [[nodiscard]] explicit constexpr forwarding_ref(reference_type ref_ LIFETIMEBOUND) noexcept : ref{ &ref_ } {}
+  [[nodiscard]] constexpr operator reference_type() noexcept LIFETIMEBOUND { return static_cast<reference_type>(*ref); }
+
+private:
+  pointer_type ref;
+};
+
+template<typename T> forwarding_ref(T &&) -> forwarding_ref<T &&>;
+
+
+}// namespace lefticus::tools
+
+#endif

include/lefticus/tools/has_move_ctor.hpp

@@ -0,0 +1,60 @@
+/*
+This is free and unencumbered software released into the public domain.
+
+Anyone is free to copy, modify, publish, use, compile, sell, or
+distribute this software, either in source code form or as a compiled
+binary, for any purpose, commercial or non-commercial, and by any
+means.
+
+In jurisdictions that recognize copyright laws, the author or authors
+of this software dedicate any and all copyright interest in the
+software to the public domain. We make this dedication for the benefit
+of the public at large and to the detriment of our heirs and
+successors. We intend this dedication to be an overt act of
+relinquishment in perpetuity of all present and future rights to this
+software under copyright law.
+
+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 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.
+
+For more information, please refer to <https://unlicense.org>
+*/
+
+
+#ifndef LEFTICUS_TOOLS_HAS_MOVE_CTOR_HPP
+#define LEFTICUS_TOOLS_HAS_MOVE_CTOR_HPP
+
+#include <concepts>
+
+namespace lefticus::tools {
+
+template<class P> struct DetectMoveConstruction
+{
+  operator P const &();
+  operator P &&();
+};
+
+template<typename T>
+concept copyable_xor_moveable = requires(T t, DetectMoveConstruction<T> m)
+{
+  // borrowed from
+  // https://stackoverflow.com/questions/51901837/how-to-get-if-a-type-is-truly-move-constructible/51912859#51912859
+  // if this line below compiles then we know we only have either
+  // a move assignment or a copy assignment, otherwise
+  // it would be ambiguous
+  // we cannot detect the constructor because MSVC
+  // seems to have a bug, but we can detect assignment!
+  t = m;
+};
+
+template<typename T>
+concept has_move_ctor = std::move_constructible<T> && !copyable_xor_moveable<T>;
+
+}// namespace lefticus::tools
+
+#endif

include/lefticus/tools/lifetimebound.hpp

@@ -0,0 +1,41 @@
+/*
+This is free and unencumbered software released into the public domain.
+
+Anyone is free to copy, modify, publish, use, compile, sell, or
+distribute this software, either in source code form or as a compiled
+binary, for any purpose, commercial or non-commercial, and by any
+means.
+
+In jurisdictions that recognize copyright laws, the author or authors
+of this software dedicate any and all copyright interest in the
+software to the public domain. We make this dedication for the benefit
+of the public at large and to the detriment of our heirs and
+successors. We intend this dedication to be an overt act of
+relinquishment in perpetuity of all present and future rights to this
+software under copyright law.
+
+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 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.
+
+For more information, please refer to <https://unlicense.org>
+*/
+
+
+#ifndef LEFTICUS_TOOLS_LIFETIMEBOUND_HPP
+#define LEFTICUS_TOOLS_LIFETIMEBOUND_HPP
+
+
+#if defined(__has_cpp_attribute)
+#if __has_cpp_attribute(clang::lifetimebound)
+#define LIFETIMEBOUND [[clang::lifetimebound]]
+#else
+#define LIFETIMEBOUND
+#endif
+#endif
+
+#endif

include/lefticus/tools/moving_ref.hpp

@@ -1,53 +1,68 @@
-#ifndef LEFTICUS_TOOLS_MOVING_REF_HPP
-#define LEFTICUS_TOOLS_MOVING_REF_HPP
+/*
+This is free and unencumbered software released into the public domain.
 
-#include <type_traits>
-#include <utility>
+Anyone is free to copy, modify, publish, use, compile, sell, or
+distribute this software, either in source code form or as a compiled
+binary, for any purpose, commercial or non-commercial, and by any
+means.
 
-namespace lefticus {
+In jurisdictions that recognize copyright laws, the author or authors
+of this software dedicate any and all copyright interest in the
+software to the public domain. We make this dedication for the benefit
+of the public at large and to the detriment of our heirs and
+successors. We intend this dedication to be an overt act of
+relinquishment in perpetuity of all present and future rights to this
+software under copyright law.
 
+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 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.
 
-#ifdef __cpp_concepts
-template<class P>
-struct DetectMoveConstruction
-{
-    constexpr operator P const&();
-    constexpr operator P&&();
-};
+For more information, please refer to <https://unlicense.org>
+*/
+
+
+#ifndef LEFTICUS_TOOLS_MOVING_REF_HPP
+#define LEFTICUS_TOOLS_MOVING_REF_HPP
+
+#include "has_move_ctor.hpp"
+#include "lifetimebound.hpp"
+
+namespace lefticus::tools {
 
 template<typename T>
-concept copyable_xor_moveable = requires (T t, DetectMoveConstruction<T> m) {
-  // borrowed from https://stackoverflow.com/questions/51901837/how-to-get-if-a-type-is-truly-move-constructible/51912859#51912859
-  // if this line below compiles then we know we only have either
-  // a move assignment or a copy assignment, otherwise
-  // it would be ambiguous
-  // we cannot detect the constructor because MSVC
-  // seems to have a bug, but we can detect assignment!
-  t = m;
-};
+concept movable = std::is_move_constructible_v<T> && std::is_move_assignable_v<T> && not std::is_const_v<
+                    T> && not std::is_pointer_v<T> && not std::is_reference_v<T>;
 
 template<typename T>
-concept has_move_ctor = 
-  std::move_constructible<T> && !copyable_xor_moveable<T>;
-#endif
+requires movable<T> && has_move_ctor<T>
+struct [[nodiscard]] moving_ref
+{
+  using value_type = T;
+  using pointer_type = std::add_pointer_t<T>;
+  using reference_type = std::add_rvalue_reference_t<T>;
 
+  moving_ref(moving_ref &&) = delete (
+    "you accidentally moved a ref (auto obj = std::move(ref)) instead of (Type obj = ref)");
+  moving_ref(const moving_ref &) = delete (
+    "you accidentally copied a ref (auto obj = ref) instead of (Type obj = ref)");
+  moving_ref &operator=(moving_ref &&) = delete ("you accidentally move assigned a ref (ref = std::move(other_ref))");
+  moving_ref &operator=(const moving_ref &) = delete ("you accidentally copy assigned a ref (ref = other_ref)");
 
+  [[nodiscard]] explicit constexpr moving_ref(reference_type ref_ LIFETIMEBOUND) noexcept : ref{ &ref_ } {}
 
-#ifdef __cpp_concepts
-template<has_move_ctor T>
-#else
-template<typename T>
-#endif
+  moving_ref(const T &) = delete ("this type is only to be used with rvalue reference parameters");
 
-struct moving_ref {
-    constexpr moving_ref(T &&val) : ref{std::move(val)} {}
-    constexpr operator T&&() {
-        return std::move(ref);
-    }
-    T &&ref;
+  [[nodiscard]] constexpr operator reference_type() noexcept LIFETIMEBOUND { return static_cast<reference_type>(*ref); }
+
+private:
+  pointer_type ref;
 };
 
-}
+}// namespace lefticus::tools
 
 #endif
-

include/lefticus/tools/non_promoting_ints.hpp

@@ -245,22 +245,22 @@ using int_np64_t = int_np<std::int64_t>;
 
 namespace literals {
 
-  consteval auto operator"" _npu8(unsigned long long val) { return uint_np8_t::from(val); }
+  consteval auto operator""_npu8(unsigned long long val) { return uint_np8_t::from(val); }
 
-  consteval auto operator"" _npu16(unsigned long long val) { return uint_np16_t::from(val); }
+  consteval auto operator""_npu16(unsigned long long val) { return uint_np16_t::from(val); }
 
-  consteval auto operator"" _npu32(unsigned long long val) { return uint_np32_t::from(val); }
+  consteval auto operator""_npu32(unsigned long long val) { return uint_np32_t::from(val); }
 
-  consteval auto operator"" _npu64(unsigned long long val) { return uint_np64_t::from(val); }
+  consteval auto operator""_npu64(unsigned long long val) { return uint_np64_t::from(val); }
 
 
-  consteval auto operator"" _np8(unsigned long long val) { return int_np8_t::from(val); }
+  consteval auto operator""_np8(unsigned long long val) { return int_np8_t::from(val); }
 
-  consteval auto operator"" _np16(unsigned long long val) { return int_np16_t::from(val); }
+  consteval auto operator""_np16(unsigned long long val) { return int_np16_t::from(val); }
 
-  consteval auto operator"" _np32(unsigned long long val) { return int_np32_t::from(val); }
+  consteval auto operator""_np32(unsigned long long val) { return int_np32_t::from(val); }
 
-  consteval auto operator"" _np64(unsigned long long val) { return int_np64_t::from(val); }
+  consteval auto operator""_np64(unsigned long long val) { return int_np64_t::from(val); }
 }// namespace literals
 
 }// namespace lefticus::tools

include/lefticus/tools/polymorphic_variant.hpp

@@ -0,0 +1,74 @@
+#ifndef LEFTICUS_TOOLS_POLYMORPHIC_VARIANT_HPP
+#define LEFTICUS_TOOLS_POLYMORPHIC_VARIANT_HPP
+
+namespace lefticus::tools {
+template<typename Base, typename... Type> const Base *get_base(const std::variant<Type...> &input)
+{
+  const Base *retval = nullptr;
+
+  ((retval = retval ? retval : std::get_if<Type>(&input)), ...);
+
+  return retval;
+}
+
+template<typename Base, typename... Type_List> Base *get_base(std::variant<Type_List...> &input)
+{
+  Base *retval = nullptr;
+
+  ((retval = retval ? retval : std::get_if<Type_List>(&input)), ...);
+
+  return retval;
+}
+
+// a variant-based type that allows polymorphic access to the underlying
+// data
+template<typename Base, typename... Derived>
+requires std::is_polymorphic_v<Base> &&(std::is_base_of_v<Base, Derived> &&...)
+  && (std::is_final_v<Derived> && ...) class polymorphic_variant
+{
+public:
+  polymorphic_variant() = delete;
+
+  using concrete_Type_List = Type_List<Derived...>;
+  using contained_type = decltype(variant_type(concrete_Type_List{}));
+
+  // allow any of the non-abstract supported Type_List in
+  template<typename Param>
+  constexpr explicit polymorphic_variant(
+    Param &&p) requires contains_type_v<std::remove_cvref_t<Param>, concrete_Type_List>
+    : value{ std::forward<Param>(p) }
+  {}
+
+  // anything that isn't an exact match for one of the supported Type_List
+  // is deleted. Why? We don't want to slice!
+  template<typename Param> constexpr explicit polymorphic_variant(Param &&) = delete;
+
+  template<typename T, typename... Args>
+  constexpr explicit polymorphic_variant(std::in_place_type_t<T> ipt, Args &&...args)
+    : value(ipt, std::forward<Args>(args)...)
+  {}
+
+  [[nodiscard]] constexpr Base *get() { return get_base<Base>(value); }
+  [[nodiscard]] constexpr const Base *get() const { return get_base<Base>(value); }
+
+  [[nodiscard]] constexpr Base &operator*() { return *get(); }
+  [[nodiscard]] constexpr const Base &operator*() const { return *get(); }
+
+  [[nodiscard]] constexpr Base *operator->() { return get(); }
+  [[nodiscard]] constexpr const Base *operator->() const { return get(); }
+
+private:
+  [[nodiscard]] constexpr static auto getter() noexcept
+  {
+    return [](auto &obj) -> Base * { return &obj; };
+  }
+
+  [[nodiscard]] constexpr static auto const_getter() noexcept
+  {
+    return [](const auto &obj) -> const Base * { return &obj; };
+  }
+
+  contained_type value;
+};
+}// namespace lefticus::tools
+#endif