added standard check

Author: dk949

include/mt_queue/include/ut/mt_queue/mt_queue.hpp

@@ -1,6 +1,10 @@
 #ifndef UT_MT_QUEUE_HPP
 #define UT_MT_QUEUE_HPP
 
+#if __cplusplus < 202'002L
+#    error this file has to be compiled with at least C++20
+#endif
+
 #include <condition_variable>
 #include <deque>
 #include <mutex>

include/ptr_containers/include/ut/ptr_containers/container_base.hpp

@@ -1,6 +1,10 @@
 #ifndef CONTAINER_BASE_HPP
 #define CONTAINER_BASE_HPP
 
+#if __cplusplus < 202'002L
+#    error this file has to be compiled with at least C++20
+#endif
+
 #include "template_helpers.hpp"
 
 #ifndef assert
@@ -171,7 +175,7 @@ namespace detail {
 }
 
 template<typename T>
-struct IsDerivedFromContainerBase : decltype(detail::derivedFromContainerBase(std::declval<T *>())) { };
+struct IsDerivedFromContainerBase : decltype(detail::derivedFromContainerBase(std::declval<T *>())) {};
 
 template<typename T>
 inline constexpr bool IsDerivedFromContainerBaseV = IsDerivedFromContainerBase<T>::value;

include/ptr_containers/include/ut/ptr_containers/ownptrvec.hpp

@@ -1,6 +1,10 @@
 #ifndef OWNPTRVEC_HPP
 #define OWNPTRVEC_HPP
 
+#if __cplusplus < 202'002L
+#    error this file has to be compiled with at least C++20
+#endif
+
 #include "container_base.hpp"
 #include "ptrvecview.hpp"
 #include "template_helpers.hpp"

include/ptr_containers/include/ut/ptr_containers/ptrvecview.hpp

@@ -1,6 +1,10 @@
 #ifndef PTRVECVIEW_HPP
 #define PTRVECVIEW_HPP
 
+#if __cplusplus < 202'002L
+#    error this file has to be compiled with at least C++20
+#endif
+
 #include "container_base.hpp"
 
 #define BASE                                    \

include/ptr_containers/include/ut/ptr_containers/template_helpers.hpp

@@ -1,5 +1,10 @@
 #ifndef CONCEPTS_HPP
 #define CONCEPTS_HPP
+
+#if __cplusplus < 202'002L
+#    error this file has to be compiled with at least C++20
+#endif
+
 #include <concepts>
 #include <memory>
 

include/ptr_containers/include/ut/ptr_containers/valueptr.hpp

@@ -1,5 +1,10 @@
 #ifndef VALUEPTR_HPP
 #define VALUEPTR_HPP
+
+#if __cplusplus < 202'002L
+#    error this file has to be compiled with at least C++20
+#endif
+
 #include "template_helpers.hpp"
 
 #include <memory>

include/resource/include/ut/resource/optionalof.hpp

@@ -1,5 +1,10 @@
 #ifndef UT_OPTIONALOF_HPP
 #define UT_OPTIONALOF_HPP
+
+#if __cplusplus < 202'002L
+#    error this file has to be compiled with at least C++20
+#endif
+
 #include <optional>
 #include <type_traits>
 

include/resource/include/ut/resource/resource.hpp

@@ -1,5 +1,10 @@
 #ifndef UT_RESOURCE_HPP
 #define UT_RESOURCE_HPP
+
+#if __cplusplus < 202'002L
+#    error this file has to be compiled with at least C++20
+#endif
+
 #include "optionalof.hpp"
 
 #include <type_traits>

include/static_string/include/ut/static_string/static_string.hpp

@@ -1,6 +1,10 @@
 #ifndef UT_STATIC_STRING_HPP
 #define UT_STATIC_STRING_HPP
 
+#if __cplusplus < 202002L
+#error this file has to be compiled with at least C++20
+#endif
+
 /**Usage:
  * std >= c++20 (c++23)
  * // typedef using `char`