Bump to C++20

CMakeLists.txt

@@ -21,6 +21,7 @@ include(cmake/get_nwx_cmake.cmake)
 include(get_version_from_git)
 get_version_from_git(utilities_version "${CMAKE_CURRENT_LIST_DIR}")
 project(utilities VERSION "${utilities_version}" LANGUAGES CXX)
+set(CMAKE_CXX_STANDARD 20)
 
 include(nwx_versions)
 include(get_cmaize)

include/utilities/iterators/input_iterator_base.hpp

@@ -153,7 +153,7 @@ class InputIteratorBase {
      *  @return true if the two iterators are equal and false otherwise.
      *  @throws None. No throw guarantee
      */
-    bool operator==(const ParentType& rhs) const noexcept;
+    bool operator==(const InputIteratorBase& rhs) const noexcept;
 
     /** @brief Determines if two iterators point to different elements.
      *
@@ -166,7 +166,7 @@ class InputIteratorBase {
      *  @return false if the two iterators are equal and true otherwise.
      *  @throws None. No throw guarantee
      */
-    bool operator!=(const ParentType& rhs) const noexcept;
+    bool operator!=(const InputIteratorBase& rhs) const noexcept;
 
 protected:
     /// Downcasts this to a read-/write-able instance of the derived class
@@ -187,13 +187,13 @@ ParentType InputIteratorBase<ParentType>::operator++(int) {
 
 template<typename ParentType>
 bool InputIteratorBase<ParentType>::operator==(
-  const ParentType& rhs) const noexcept {
-    return downcast_().are_equal(rhs);
+  const InputIteratorBase& rhs) const noexcept {
+    return downcast_().are_equal(rhs.downcast_());
 }
 
 template<typename ParentType>
 bool InputIteratorBase<ParentType>::operator!=(
-  const ParentType& rhs) const noexcept {
+  const InputIteratorBase& rhs) const noexcept {
     return !((*this) == rhs);
 }
 

tests/unit_tests/type_traits/type_traits_extensions.cpp

@@ -23,7 +23,7 @@ using namespace utilities;
 struct Struct1 {
     void begin();
     void swap(Struct1&);
-    bool operator!=(const Struct1&);
+    bool operator!=(const Struct1&) const;
     int operator*();
     int operator++(int);
     int operator[](int);
@@ -34,7 +34,7 @@ struct Struct1 {
 };
 struct Struct2 {
     using value_type = int;
-    bool operator==(const Struct2&);
+    bool operator==(const Struct2&) const;
     int operator++();
     Struct2* operator->();
     int operator--();