diff --git a/include/cppmp/config.h b/include/cppmp/config.h
new file mode 100644
index 0000000..324337d
--- /dev/null
+++ b/include/cppmp/config.h
@@ -0,0 +1,185 @@
+#pragma once
+
+/* C++ standards */
+
+#if __cplusplus >= 201103L
+    #define cppmp_supports_cpp11 1
+#endif
+#if __cplusplus >= 201402L
+    #define cppmp_supports_cpp14 1
+#endif
+#if __cplusplus >= 201703L
+    #define cppmp_supports_cpp17 1
+#endif
+
+/* C++ features */
+
+#if __cpp_variable_templates >= 201304L
+    #define cppmp_supports_variable_templates 1
+#endif
+
+#if __cpp_constexpr >= 201603L
+    #define cppmp_supports_constexpr_lambda 1
+#endif
+
+/* GCC */
+
+#ifdef __GNUC__
+    #define cppmp_gcc_version (__GNUC__       * 10000   \
+                            + __GNUC_MINOR__ * 100     \
+                            + __GNUC_PATCHLEVEL__)
+#endif
+
+/* Macros */
+
+#ifdef cppmp_supports_constexpr_lambda
+    #define cppmp_constexpr_lambda constexpr
+#else
+    #define cppmp_constexpr_lambda
+#endif
+
+/* Supported Traits */
+
+#ifdef cppmp_supports_cpp11
+    #define cppmp_std_supports_remove_const 1
+    #define cppmp_std_supports_remove_volatile 1
+    #define cppmp_std_supports_remove_cv 1
+    #define cppmp_std_supports_add_const 1
+    #define cppmp_std_supports_add_volatile 1
+    #define cppmp_std_supports_add_cv 1
+
+    #define cppmp_std_supports_remove_reference 1
+    #define cppmp_std_supports_add_lvalue_reference 1
+    #define cppmp_std_supports_add_rvalue_reference 1
+
+    #define cppmp_std_supports_make_signed 1
+    #define cppmp_std_supports_make_unsigned 1
+
+    #define cppmp_std_supports_remove_extent 1
+    #define cppmp_std_supports_remove_all_extents 1
+
+    #define cppmp_std_supports_add_pointer 1
+    #define cppmp_std_supports_remove_pointer 1
+
+    #define cppmp_std_supports_decay 1
+    #define cppmp_std_supports_common_type 1
+    #define cppmp_std_supports_underlying_type 1
+    #define cppmp_std_supports_aligned_storage 1
+
+    #if !defined(cppmp_gcc_version) or cppmp_gcc_version >= 50000
+        #define cppmp_std_supports_aligned_union 1
+    #endif
+
+    #ifndef cppmp_supports_cpp20
+        #define cppmp_std_supports_result_of 1
+    #endif
+
+    #define cppmp_std_supports_enable_if 1
+    #define cppmp_std_supports_conditional 1
+
+    #define cppmp_std_supports_is_void 1
+    #define cppmp_std_supports_is_integral 1
+    #define cppmp_std_supports_is_floating_point 1
+    #define cppmp_std_supports_is_array 1
+    #define cppmp_std_supports_is_pointer 1
+    #define cppmp_std_supports_is_lvalue_reference 1
+    #define cppmp_std_supports_is_rvalue_reference 1
+    #define cppmp_std_supports_is_member_object_pointer 1
+    #define cppmp_std_supports_is_member_function_pointer 1
+    #define cppmp_std_supports_is_enum 1
+    #define cppmp_std_supports_is_union 1
+    #define cppmp_std_supports_is_class 1
+    #define cppmp_std_supports_is_function 1
+    #define cppmp_std_supports_is_reference 1
+    #define cppmp_std_supports_is_arithmetic 1
+    #define cppmp_std_supports_is_fundamental 1
+    #define cppmp_std_supports_is_object 1
+    #define cppmp_std_supports_is_scalar 1
+    #define cppmp_std_supports_is_compound 1
+    #define cppmp_std_supports_is_member_pointer 1
+    #define cppmp_std_supports_is_const 1
+    #define cppmp_std_supports_is_volatile 1
+    #define cppmp_std_supports_is_trivial 1
+    #define cppmp_std_supports_is_standard_layout 1
+    #define cppmp_std_supports_is_pod 1
+    #define cppmp_std_supports_is_empty 1
+    #define cppmp_std_supports_is_polymorphic 1
+    #define cppmp_std_supports_is_abstract 1
+    #define cppmp_std_supports_is_signed 1
+    #define cppmp_std_supports_is_unsigned 1
+
+    #define cppmp_std_supports_is_constructible 1
+    #define cppmp_std_supports_is_default_constructible 1
+    #define cppmp_std_supports_is_copy_constructible 1
+    #define cppmp_std_supports_is_move_constructible 1
+    #define cppmp_std_supports_is_assignable 1
+    #define cppmp_std_supports_is_copy_assignable 1
+    #define cppmp_std_supports_is_move_assignable 1
+    #define cppmp_std_supports_is_destructible 1
+
+    #if !defined(cppmp_gcc_version) or cppmp_gcc_version >= 50000
+        #define cppmp_std_supports_is_trivially_constructible 1
+        #define cppmp_std_supports_is_trivially_default_constructible 1
+        #define cppmp_std_supports_is_trivially_copy_constructible 1
+        #define cppmp_std_supports_is_trivially_move_constructible 1
+        #define cppmp_std_supports_is_trivially_assignable 1
+        #define cppmp_std_supports_is_trivially_copy_assignable 1
+        #define cppmp_std_supports_is_trivially_move_assignable 1
+        #define cppmp_std_supports_is_trivially_destructible 1
+        #define cppmp_std_supports_is_trivially_copyable 1
+    #endif
+
+    #define cppmp_std_supports_is_nothrow_constructible 1
+    #define cppmp_std_supports_is_nothrow_default_constructible 1
+    #define cppmp_std_supports_is_nothrow_copy_constructible 1
+    #define cppmp_std_supports_is_nothrow_move_constructible 1
+    #define cppmp_std_supports_is_nothrow_assignable 1
+    #define cppmp_std_supports_is_nothrow_copy_assignable 1
+    #define cppmp_std_supports_is_nothrow_move_assignable 1
+    #define cppmp_std_supports_is_nothrow_destructible 1
+
+    #define cppmp_std_supports_has_virtual_destructor 1
+
+    #define cppmp_std_supports_alignment_of 1
+    #define cppmp_std_supports_rank 1
+    #define cppmp_std_supports_extent 1
+
+    #define cppmp_std_supports_is_same 1
+    #define cppmp_std_supports_is_base_of 1
+    #define cppmp_std_supports_is_convertible 1
+#endif
+
+#ifdef cppmp_supports_cpp14
+    #define cppmp_std_supports_is_null_pointer 1
+    #define cppmp_std_supports_is_final 1
+#endif
+
+#ifdef cppmp_supports_cpp17
+    #define cppmp_std_supports_invoke_result 1
+
+    #define cppmp_std_supports_conjunction 1
+    #define cppmp_std_supports_disjunction 1
+    #define cppmp_std_supports_negation 1
+
+    #define cppmp_std_supports_is_aggregate 1
+    #define cppmp_std_supports_is_swappable_with 1
+    #define cppmp_std_supports_is_swappable 1
+    #define cppmp_std_supports_is_nothrow_swappable_with 1
+    #define cppmp_std_supports_is_nothrow_swappable 1
+    #define cppmp_std_supports_has_unique_object_representations 1
+    #define cppmp_std_supports_is_invocable 1
+    #define cppmp_std_supports_is_invocable_r 1
+    #define cppmp_std_supports_is_nothrow_invocable 1
+    #define cppmp_std_supports_is_nothrow_invocable_r 1
+#endif
+
+#ifdef cppmp_supports_cpp20
+    #define cppmp_std_supports_remove_cvref 1
+
+    #define cppmp_std_supports_is_bounded_array 1
+    #define cppmp_std_supports_is_unbounded_array 1
+    #define cppmp_std_supports_has_strong_structural_equality 1
+    #define cppmp_std_supports_is_nothrow_convertible 1
+    #define cppmp_std_supports_is_layout_compatible 1
+    #define cppmp_std_supports_is_pointer_interconvertible_base_of 1
+#endif
diff --git a/include/cppmp/core/checker.h b/include/cppmp/core/checker.h
index 6709161..7595806 100644
--- a/include/cppmp/core/checker.h
+++ b/include/cppmp/core/checker.h
@@ -1,30 +1,45 @@
 #pragma once
 
+#include "types.h"
+#include "../config.h"
+
+
 #define cppmp_define_checker(name) \
     template<typename... T> \
     struct name \
         : public integral_constant<decltype(std::name<T...>::value), std::name<T...>::value> \
         { }; \
     \
-    template<typename... T> \
-    constexpr decltype(auto) name ## _v = name<T...>::value;
+    cppmp_define_checker_var(name)
 
-#include "types.h"
+#ifdef cppmp_supports_variable_templates
+    #define cppmp_define_checker_var(name) \
+        template<typename... T> \
+        constexpr decltype(auto) name ## _v = name<T...>::value;
+#else
+    #define cppmp_define_checker_var(name)
+#endif
 
 namespace cppmp
 {
 
+    namespace __impl
+    {
+
+        template<typename T>
+        struct is_valid;
+
+    }
+
     /**
      * @brief Evaluates to true_t if the passed template parameters are valid, false_t otherwise.
      */
-    template<typename T, typename = void>
-    struct is_valid;
+    template<typename T>
+    struct is_valid
+        : public __impl::is_valid<T>
+        { };
 
-    /**
-     * @brief Is true if the passed template parameters are valid, false otherwise.
-     */
-    template<typename... T>
-    constexpr decltype(auto) is_valid_v = is_valid<T...>::value;
+    cppmp_define_checker_var(is_valid)
 
     /**
      * @brief Evaluates to true_t if T is a specialization if T_template, false_t otherwise.
@@ -32,11 +47,10 @@ namespace cppmp
     template<typename T, template <typename...> class T_template>
     struct is_specialization_of;
 
-    /**
-     * @brief Evaluates to true if T is a specialization if T_template, false otherwise.
-     */
+    #ifdef cppmp_supports_variable_templates
     template<typename T, template <typename...> class T_template>
     constexpr decltype(auto) is_specialization_of_v = is_specialization_of<T, T_template>::value;
+    #endif
 
     /**
      * @brief Evaluates to true_t if all passed parameters are true, false_t otherwise.
@@ -44,93 +58,345 @@ namespace cppmp
     template<bool... B>
     struct is_true;
 
-    /**
-     * @brief Evaluates to true if all passed parameters are true, false otherwise.
-     */
+    #ifdef cppmp_supports_variable_templates
     template<bool... B>
     constexpr decltype(auto) is_true_v = is_true<B...>::value;
+    #endif
+
+    /* primary type categories */
 
+    #ifdef cppmp_std_supports_is_void
     cppmp_define_checker(is_void);
+    #endif
+
+    #ifdef cppmp_std_supports_is_null_pointer
     cppmp_define_checker(is_null_pointer);
+    #endif
+
+    #ifdef cppmp_std_supports_is_integral
     cppmp_define_checker(is_integral);
+    #endif
+
+    #ifdef cppmp_std_supports_is_floating_point
     cppmp_define_checker(is_floating_point);
+    #endif
+
+    #ifdef cppmp_std_supports_is_array
     cppmp_define_checker(is_array);
-    cppmp_define_checker(is_enum);
-    cppmp_define_checker(is_union);
-    cppmp_define_checker(is_class);
-    cppmp_define_checker(is_function);
+    #endif
+
+    #ifdef cppmp_std_supports_is_pointer
     cppmp_define_checker(is_pointer);
+    #endif
+
+    #ifdef cppmp_std_supports_is_lvalue_reference
     cppmp_define_checker(is_lvalue_reference);
+    #endif
+
+    #ifdef cppmp_std_supports_is_rvalue_reference
     cppmp_define_checker(is_rvalue_reference);
+    #endif
+
+    #ifdef cppmp_std_supports_is_member_object_pointer
     cppmp_define_checker(is_member_object_pointer);
+    #endif
+
+    #ifdef cppmp_std_supports_is_member_function_pointer
     cppmp_define_checker(is_member_function_pointer);
-    cppmp_define_checker(is_fundamental);
+    #endif
+
+    #ifdef cppmp_std_supports_is_enum
+    cppmp_define_checker(is_enum);
+    #endif
+
+    #ifdef cppmp_std_supports_is_union
+    cppmp_define_checker(is_union);
+    #endif
+
+    #ifdef cppmp_std_supports_is_class
+    cppmp_define_checker(is_class);
+    #endif
+
+    #ifdef cppmp_std_supports_is_function
+    cppmp_define_checker(is_function);
+    #endif
+
+
+    /* composite type categories */
+
+    #ifdef cppmp_std_supports_is_reference
+    cppmp_define_checker(is_reference);
+    #endif
+
+    #ifdef cppmp_std_supports_is_arithmetic
     cppmp_define_checker(is_arithmetic);
-    cppmp_define_checker(is_scalar);
+    #endif
+
+    #ifdef cppmp_std_supports_is_fundamental
+    cppmp_define_checker(is_fundamental);
+    #endif
+
+    #ifdef cppmp_std_supports_is_object
     cppmp_define_checker(is_object);
+    #endif
+
+    #ifdef cppmp_std_supports_is_scalar
+    cppmp_define_checker(is_scalar);
+    #endif
+
+    #ifdef cppmp_std_supports_is_compound
     cppmp_define_checker(is_compound);
-    cppmp_define_checker(is_reference);
+    #endif
+
+    #ifdef cppmp_std_supports_is_member_pointer
     cppmp_define_checker(is_member_pointer);
+    #endif
+
+    /* type properties */
+
+    #ifdef cppmp_std_supports_is_const
     cppmp_define_checker(is_const);
+    #endif
+
+    #ifdef cppmp_std_supports_is_volatile
     cppmp_define_checker(is_volatile);
+    #endif
+
+    #ifdef cppmp_std_supports_is_trivial
     cppmp_define_checker(is_trivial);
+    #endif
+
+    #ifdef cppmp_std_supports_is_trivially_copyable
     cppmp_define_checker(is_trivially_copyable);
+    #endif
+
+    #ifdef cppmp_std_supports_is_standard_layout
     cppmp_define_checker(is_standard_layout);
+    #endif
+
+    #ifdef cppmp_std_supports_is_pod
     cppmp_define_checker(is_pod);
-    cppmp_define_checker(is_literal_type);
+    #endif
+
+    #ifdef cppmp_std_supports_is_empty
     cppmp_define_checker(is_empty);
+    #endif
+
+    #ifdef cppmp_std_supports_is_polymorphic
     cppmp_define_checker(is_polymorphic);
+    #endif
+
+    #ifdef cppmp_std_supports_is_abstract
     cppmp_define_checker(is_abstract);
+    #endif
+
+    #ifdef cppmp_std_supports_is_final
     cppmp_define_checker(is_final);
+    #endif
+
+    #ifdef cppmp_std_supports_is_aggregate
+    cppmp_define_checker(is_aggregate);
+    #endif
+
+    #ifdef cppmp_std_supports_is_signed
     cppmp_define_checker(is_signed);
+    #endif
+
+    #ifdef cppmp_std_supports_is_unsigned
     cppmp_define_checker(is_unsigned);
+    #endif
+
+    #ifdef cppmp_std_supports_is_bounded_array
+    cppmp_define_checker(is_bounded_array);
+    #endif
+
+    #ifdef cppmp_std_supports_is_unbounded_array
+    cppmp_define_checker(is_unbounded_array);
+    #endif
+
+    #ifdef cppmp_std_supports_is_constructible
     cppmp_define_checker(is_constructible);
-    cppmp_define_checker(is_trivially_constructible);
-    cppmp_define_checker(is_nothrow_constructible);
+    #endif
+
+    #ifdef cppmp_std_supports_is_default_constructible
     cppmp_define_checker(is_default_constructible);
-    cppmp_define_checker(is_trivially_default_constructible);
-    cppmp_define_checker(is_nothrow_default_constructible);
+    #endif
+
+    #ifdef cppmp_std_supports_is_copy_constructible
     cppmp_define_checker(is_copy_constructible);
-    cppmp_define_checker(is_trivially_copy_constructible);
-    cppmp_define_checker(is_nothrow_copy_constructible);
+    #endif
+
+    #ifdef cppmp_std_supports_is_move_constructible
     cppmp_define_checker(is_move_constructible);
-    cppmp_define_checker(is_trivially_move_constructible);
-    cppmp_define_checker(is_nothrow_move_constructible);
+    #endif
+
+    #ifdef cppmp_std_supports_is_assignable
     cppmp_define_checker(is_assignable);
-    cppmp_define_checker(is_trivially_assignable);
-    cppmp_define_checker(is_nothrow_assignable);
+    #endif
+
+    #ifdef cppmp_std_supports_is_copy_assignable
     cppmp_define_checker(is_copy_assignable);
-    cppmp_define_checker(is_trivially_copy_assignable);
-    cppmp_define_checker(is_nothrow_copy_assignable);
+    #endif
+
+    #ifdef cppmp_std_supports_is_move_assignable
     cppmp_define_checker(is_move_assignable);
-    cppmp_define_checker(is_trivially_move_assignable);
-    cppmp_define_checker(is_nothrow_move_assignable);
-    cppmp_define_checker(is_destructible);
-    cppmp_define_checker(is_trivially_destructible);
-    cppmp_define_checker(is_nothrow_destructible);
-    cppmp_define_checker(has_virtual_destructor);
+    #endif
+
+    #ifdef cppmp_std_supports_is_swappable_with
     cppmp_define_checker(is_swappable_with);
+    #endif
+
+    #ifdef cppmp_std_supports_is_swappable
     cppmp_define_checker(is_swappable);
+    #endif
+
+    #ifdef cppmp_std_supports_is_destructible
+    cppmp_define_checker(is_destructible);
+    #endif
+
+    #ifdef cppmp_std_supports_is_trivially_constructible
+    cppmp_define_checker(is_trivially_constructible);
+    #endif
+
+    #ifdef cppmp_std_supports_is_trivially_default_constructible
+    cppmp_define_checker(is_trivially_default_constructible);
+    #endif
+
+    #ifdef cppmp_std_supports_is_trivially_copy_constructible
+    cppmp_define_checker(is_trivially_copy_constructible);
+    #endif
+
+    #ifdef cppmp_std_supports_is_trivially_move_constructible
+    cppmp_define_checker(is_trivially_move_constructible);
+    #endif
+
+    #ifdef cppmp_std_supports_is_trivially_assignable
+    cppmp_define_checker(is_trivially_assignable);
+    #endif
+
+    #ifdef cppmp_std_supports_is_trivially_copy_assignable
+    cppmp_define_checker(is_trivially_copy_assignable);
+    #endif
+
+    #ifdef cppmp_std_supports_is_trivially_move_assignable
+    cppmp_define_checker(is_trivially_move_assignable);
+    #endif
+
+    #ifdef cppmp_std_supports_is_trivially_destructible
+    cppmp_define_checker(is_trivially_destructible);
+    #endif
+
+    #ifdef cppmp_std_supports_is_nothrow_constructible
+    cppmp_define_checker(is_nothrow_constructible);
+    #endif
+
+    #ifdef cppmp_std_supports_is_nothrow_default_constructible
+    cppmp_define_checker(is_nothrow_default_constructible);
+    #endif
+
+    #ifdef cppmp_std_supports_is_nothrow_copy_constructible
+    cppmp_define_checker(is_nothrow_copy_constructible);
+    #endif
+
+    #ifdef cppmp_std_supports_is_nothrow_move_constructible
+    cppmp_define_checker(is_nothrow_move_constructible);
+    #endif
+
+    #ifdef cppmp_std_supports_is_nothrow_assignable
+    cppmp_define_checker(is_nothrow_assignable);
+    #endif
+
+    #ifdef cppmp_std_supports_is_nothrow_copy_assignable
+    cppmp_define_checker(is_nothrow_copy_assignable);
+    #endif
+
+    #ifdef cppmp_std_supports_is_nothrow_move_assignable
+    cppmp_define_checker(is_nothrow_move_assignable);
+    #endif
+
+    #ifdef cppmp_std_supports_is_nothrow_swappable_with
     cppmp_define_checker(is_nothrow_swappable_with);
+    #endif
+
+    #ifdef cppmp_std_supports_is_nothrow_swappable
     cppmp_define_checker(is_nothrow_swappable);
+    #endif
+
+    #ifdef cppmp_std_supports_is_nothrow_destructible
+    cppmp_define_checker(is_nothrow_destructible);
+    #endif
+
+    #ifdef cppmp_std_supports_has_virtual_destructor
+    cppmp_define_checker(has_virtual_destructor);
+    #endif
+
+    #ifdef cppmp_std_supports_has_unique_object_representations
+    cppmp_define_checker(has_unique_object_representations);
+    #endif
+
+    #ifdef cppmp_std_supports_has_strong_structural_equality
+    cppmp_define_checker(has_strong_structural_equality);
+    #endif
+
+    /* type property queries */
+
+    #ifdef cppmp_std_supports_alignment_of
     cppmp_define_checker(alignment_of);
+    #endif
+
+    #ifdef cppmp_std_supports_rank
     cppmp_define_checker(rank);
+    #endif
+
+    #ifdef cppmp_std_supports_extent
     cppmp_define_checker(extent);
+    #endif
+
+    /* type relations */
+
+    #ifdef cppmp_std_supports_is_same
     cppmp_define_checker(is_same);
+    #endif
+
+    #ifdef cppmp_std_supports_is_base_of
     cppmp_define_checker(is_base_of);
+    #endif
+
+    #ifdef cppmp_std_supports_is_convertible
     cppmp_define_checker(is_convertible);
+    #endif
 
-    #if __cplusplus >= 201703L
-    cppmp_define_checker(has_unique_object_representations);
-    cppmp_define_checker(is_aggregate);
+    #ifdef cppmp_std_supports_is_nothrow_convertible
+    cppmp_define_checker(is_nothrow_convertible);
+    #endif
+
+    #ifdef cppmp_std_supports_is_layout_compatible
+    cppmp_define_checker(is_layout_compatible);
+    #endif
+
+    #ifdef cppmp_std_supports_is_pointer_interconvertible_base_of
+    cppmp_define_checker(is_pointer_interconvertible_base_of);
+    #endif
+
+    #ifdef cppmp_std_supports_is_invocable
     cppmp_define_checker(is_invocable);
+    #endif
+
+    #ifdef cppmp_std_supports_is_invocable_r
     cppmp_define_checker(is_invocable_r);
+    #endif
+
+    #ifdef cppmp_std_supports_is_nothrow_invocable
     cppmp_define_checker(is_nothrow_invocable);
+    #endif
+
+    #ifdef cppmp_std_supports_is_nothrow_invocable_r
     cppmp_define_checker(is_nothrow_invocable_r);
     #endif
 
 }
 
 #undef cppmp_define_checker
+#undef cppmp_define_checker_var
 
 #include "checker.inl"
diff --git a/include/cppmp/core/checker.inl b/include/cppmp/core/checker.inl
index d5af25c..7dac913 100644
--- a/include/cppmp/core/checker.inl
+++ b/include/cppmp/core/checker.inl
@@ -25,24 +25,24 @@ namespace cppmp
             : public true_t
             { };
 
-    }
+        /* is_valid */
 
-    /* is_valid */
+        template<typename T, std::size_t = sizeof(T)>
+        std::true_type is_valid_impl(T *);
 
-    template<typename T, typename>
-    struct is_valid
-        : public false_t
-        { };
+        std::false_type is_valid_impl(...);
 
-    template<typename T>
-    struct is_valid<T, void_t<decltype(sizeof(T))>>
-        : public true_t
-        { };
+        template<typename T>
+        struct is_valid
+            : public decltype(is_valid_impl(std::declval<T*>()))
+            { };
 
-    template<>
-    struct is_valid<void, void>
-        : public true_t
-        { };
+        template<>
+        struct is_valid<void>
+            : public true_t
+            { };
+
+    }
 
     /* is_specialization_of */
 
diff --git a/include/cppmp/core/constants.h b/include/cppmp/core/constants.h
index 694b792..34e8cb3 100644
--- a/include/cppmp/core/constants.h
+++ b/include/cppmp/core/constants.h
@@ -5,12 +5,6 @@
 namespace cppmp
 {
 
-    /**
-     * @brief Boolean constant value.
-     */
-    template<bool B>
-    constexpr bool_t<B> bool_c;
-
     /**
      * @brief True boolean constant value.
      */
@@ -21,15 +15,25 @@ namespace cppmp
      */
     constexpr false_t false_c;
 
+    /**
+     * @brief Zero size constant value,
+     */
+    constexpr zero_t zero_c;
+
+    #ifdef cppmp_supports_variable_templates
+
+    /**
+     * @brief Boolean constant value.
+     */
+    template<bool B>
+    constexpr bool_t<B> bool_c;
+
     /**
      * @brief Size constant value.
      */
     template<std::size_t I>
     constexpr size_t<I> size_c;
 
-    /**
-     * @brief Zero size constant value,
-     */
-    constexpr zero_t zero_c;
+    #endif
 
 }
diff --git a/include/cppmp/core/modifier.h b/include/cppmp/core/modifier.h
index 4c1b2e5..be37d2c 100644
--- a/include/cppmp/core/modifier.h
+++ b/include/cppmp/core/modifier.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <cstddef>
+
 #define cppmp_define_modifier(name) \
     template<typename... T> \
     struct name \
@@ -18,29 +20,118 @@ namespace cppmp
     template<typename T>
     using decay_t = typename decay<T>::type;
 
-    cppmp_define_modifier(remove_cv);
+    /* const-volatile modifications */
+
+    #ifdef cppmp_std_supports_remove_const
     cppmp_define_modifier(remove_const);
+    #endif
+
+    #ifdef cppmp_std_supports_remove_volatile
     cppmp_define_modifier(remove_volatile);
-    cppmp_define_modifier(add_cv);
+    #endif
+
+    #ifdef cppmp_std_supports_remove_cv
+    cppmp_define_modifier(remove_cv);
+    #endif
+
+    #ifdef cppmp_std_supports_add_const
     cppmp_define_modifier(add_const);
+    #endif
+
+    #ifdef cppmp_std_supports_add_volatile
     cppmp_define_modifier(add_volatile);
+    #endif
+
+    #ifdef cppmp_std_supports_add_cv
+    cppmp_define_modifier(add_cv);
+    #endif
+
+    /* reference modifications */
+
+    #ifdef cppmp_std_supports_remove_reference
     cppmp_define_modifier(remove_reference);
+    #endif
+
+    #ifdef cppmp_std_supports_add_lvalue_reference
     cppmp_define_modifier(add_lvalue_reference);
+    #endif
+
+    #ifdef cppmp_std_supports_add_rvalue_reference
     cppmp_define_modifier(add_rvalue_reference);
-    cppmp_define_modifier(remove_pointer);
-    cppmp_define_modifier(add_pointer);
+    #endif
+
+    /* sign modifications */
+
+    #ifdef cppmp_std_supports_make_signed
     cppmp_define_modifier(make_signed);
+    #endif
+
+    #ifdef cppmp_std_supports_make_unsigned
     cppmp_define_modifier(make_unsigned);
+    #endif
+
+    /* array modifications */
+
+    #ifdef cppmp_std_supports_remove_extent
     cppmp_define_modifier(remove_extent);
+    #endif
+
+    #ifdef cppmp_std_supports_remove_all_extents
     cppmp_define_modifier(remove_all_extents);
+    #endif
+
+    /* pointer modifications */
+
+    #ifdef cppmp_std_supports_add_pointer
+    cppmp_define_modifier(add_pointer);
+    #endif
+
+    #ifdef cppmp_std_supports_remove_pointer
+    cppmp_define_modifier(remove_pointer);
+    #endif
+
+    /* other transformations */
+
+    #ifdef cppmp_std_supports_remove_cvref
+    cppmp_define_modifier(remove_cvref);
+    #endif
+
+    #ifdef cppmp_std_supports_common_type
     cppmp_define_modifier(common_type);
+    #endif
+
+    #ifdef cppmp_std_supports_underlying_type
     cppmp_define_modifier(underlying_type);
+    #endif
+
+    #ifdef cppmp_std_supports_result_of
     cppmp_define_modifier(result_of);
+    #endif
 
-    #if __cplusplus >= 201703L
+    #ifdef cppmp_std_supports_invoke_result
     cppmp_define_modifier(invoke_result);
     #endif
 
+    #ifdef cppmp_std_supports_aligned_storage
+    template <std::size_t Len, std::size_t Align>
+    struct aligned_storage
+        : public std::aligned_storage<Len, Align>
+        { };
+
+    template <std::size_t Len, std::size_t Align>
+    using aligned_storage_t = typename aligned_storage<Len, Align>::type;
+    #endif
+
+    #ifdef cppmp_std_supports_aligned_union
+    template <std::size_t Len, class... Types>
+    struct aligned_union
+        : public std::aligned_union<Len, Types...>
+        { };
+
+    template <std::size_t Len, class... Types>
+    using aligned_union_t = typename aligned_union<Len, Types...>::type;
+    #endif
+
 }
 
 #undef cppmp_define_modifier
diff --git a/include/cppmp/core/types.h b/include/cppmp/core/types.h
index 5dffd96..4f2f8ff 100644
--- a/include/cppmp/core/types.h
+++ b/include/cppmp/core/types.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <cstddef>
 #include <type_traits>
 
 namespace cppmp
@@ -18,8 +19,10 @@ namespace cppmp
     struct type_t
         { };
 
+    #ifdef cppmp_supports_variable_templates
     template<typename X>
     constexpr decltype(auto) type_v = type_t<X> { };
+    #endif
 
     /**
      * @brief Simple type list.
diff --git a/include/cppmp/misc/generic_predicate.h b/include/cppmp/misc/generic_predicate.h
index eb907bf..0aec78f 100644
--- a/include/cppmp/misc/generic_predicate.h
+++ b/include/cppmp/misc/generic_predicate.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <utility>
 #include <cppmp/core/types.h>
 #include <cppmp/core/checker.h>
 
@@ -8,16 +9,19 @@ namespace cppmp
 
     namespace __impl
     {
+        template<typename T>
+        struct is_default_impl
+        {
+        private:
+            template<typename X>
+            static void impl(decltype(typename X::is_default(), int()));
 
-        template<typename X, typename = void>
-        struct is_valid_builder
-            : public cppmp::true_t
-            { };
+            template<typename X>
+            static bool impl(char);
 
-        template<typename X>
-        struct is_valid_builder<X, cppmp::void_t<typename X::is_default>>
-            : public cppmp::false_t
-            { };
+        public:
+            static const bool value = std::is_same<void, decltype(impl<T>(0))>::value;
+        };
 
     }
 
@@ -34,14 +38,16 @@ namespace cppmp
          */
         template<typename... T_args>
         struct is_valid
-            : public __impl::is_valid_builder<T_builder<list<T_args...>>>
+            : public bool_t<!__impl::is_default_impl<T_builder<list<T_args...>>>::value>
             { };
 
+        #ifdef cppmp_supports_variable_templates
         /**
          * @brief Evaluates to true if the passed arguments would create a valid object, false otherwise.
          */
         template<typename... T_args>
         static constexpr bool is_valid_v = is_valid<T_args...>::value;
+        #endif
 
         /**
          * @brief Invoke the builder to create the requested object.
diff --git a/include/cppmp/misc/getter.h b/include/cppmp/misc/getter.h
index 240898b..0e40242 100644
--- a/include/cppmp/misc/getter.h
+++ b/include/cppmp/misc/getter.h
@@ -29,11 +29,13 @@ namespace cppmp
     template<typename T>
     struct is_getter;
 
+    #ifdef cppmp_supports_variable_templates
     /**
      * @brief Is true if the passed type is an getter, false otherwise.
      */
     template<typename T>
     constexpr decltype(auto) is_getter_v = is_getter<T>::value;
+    #endif
 
     /**
      * @brief Predicate to create new getter objects.
diff --git a/include/cppmp/misc/getter.inl b/include/cppmp/misc/getter.inl
index b305abd..24ce87d 100644
--- a/include/cppmp/misc/getter.inl
+++ b/include/cppmp/misc/getter.inl
@@ -28,7 +28,8 @@ namespace cppmp
         template<typename T_getter>
         struct getter_builder<
             list<T_getter>,
-            enable_if_t<is_getter_v<decay_t<T_getter>>>>
+            enable_if_t<is_getter<decay_t<T_getter>>::value
+        >>
         {
             static constexpr decltype(auto) apply(T_getter&& getter)
                 { return std::forward<T_getter>(getter); }
@@ -40,7 +41,7 @@ namespace cppmp
         struct getter_builder<
             list<T_value T_object::*>,
             enable_if_t<
-                !is_valid_v<lambda_traits<T_value T_object::*>>
+                !is_valid<lambda_traits<T_value T_object::*>>::value
             >
         >
         {
@@ -54,15 +55,15 @@ namespace cppmp
 
                 member_type member;
 
-                constexpr getter_member_var(member_type p_member)
+                inline  getter_member_var(member_type p_member)
                     : member(p_member)
                     { }
 
-                constexpr getter_member_var(getter_member_var&&) = default;
-                constexpr getter_member_var(const getter_member_var&) = default;
+                inline getter_member_var(getter_member_var&&) = default;
+                inline getter_member_var(const getter_member_var&) = default;
 
-                constexpr getter_member_var& operator = (getter_member_var&&) = default;
-                constexpr getter_member_var& operator = (const getter_member_var&) = default;
+                inline getter_member_var& operator = (getter_member_var&&) = default;
+                inline getter_member_var& operator = (const getter_member_var&) = default;
 
                 template<typename X_object>
                 constexpr decltype(auto) operator()(X_object&& obj) const
@@ -92,15 +93,15 @@ namespace cppmp
 
                 member_type member;
 
-                constexpr getter_member_func(member_type p_member)
+                inline getter_member_func(member_type p_member)
                     : member(p_member)
                     { }
 
-                constexpr getter_member_func(getter_member_func&&) = default;
-                constexpr getter_member_func(const getter_member_func&) = default;
+                inline getter_member_func(getter_member_func&&) = default;
+                inline getter_member_func(const getter_member_func&) = default;
 
-                constexpr getter_member_func& operator = (getter_member_func&&) = default;
-                constexpr getter_member_func& operator = (const getter_member_func&) = default;
+                inline getter_member_func& operator = (getter_member_func&&) = default;
+                inline getter_member_func& operator = (const getter_member_func&) = default;
 
                 template<typename X_object>
                 constexpr decltype(auto) operator()(X_object&& obj) const
@@ -135,9 +136,11 @@ namespace cppmp
         struct getter_builder<
             list<T_lambda>,
             enable_if_t<
-                    is_valid_v<lambda_traits<decay_t<T_lambda>>>
+                    is_valid<lambda_traits<decay_t<T_lambda>>>::value
                 &&  lambda_traits<decay_t<T_lambda>>::argument_count_v == 1
-                && !is_void_v<typename lambda_traits<decay_t<T_lambda>>::return_type>>>
+                && !is_void<typename lambda_traits<decay_t<T_lambda>>::return_type>::value
+            >
+        >
         {
             struct getter_lambda
                 : public tag_getter
@@ -150,15 +153,15 @@ namespace cppmp
 
                 lambda_type lambda;
 
-                constexpr getter_lambda(lambda_type&& p_lambda)
+                inline getter_lambda(lambda_type&& p_lambda)
                     : lambda(std::forward<lambda_type>(p_lambda))
                     { }
 
-                constexpr getter_lambda(getter_lambda&&) = default;
-                constexpr getter_lambda(const getter_lambda&) = default;
+                inline getter_lambda(getter_lambda&&) = default;
+                inline  getter_lambda(const getter_lambda&) = default;
 
-                constexpr getter_lambda& operator = (getter_lambda&&) = default;
-                constexpr getter_lambda& operator = (const getter_lambda&) = default;
+                inline getter_lambda& operator = (getter_lambda&&) = default;
+                inline getter_lambda& operator = (const getter_lambda&) = default;
 
                 template<typename X_object>
                 constexpr decltype(auto) operator()(X_object&& obj) const
@@ -177,8 +180,8 @@ namespace cppmp
         struct getter_builder<
             list<T_first, T_second, T_rest...>,
             enable_if_t<
-                    is_valid_v<decltype(make_getter(std::declval<T_first>()))>
-                &&  is_valid_v<decltype(make_getter(std::declval<T_second>(), std::declval<T_rest>()...))>
+                    is_valid<decltype(make_getter(std::declval<T_first>()))>::value
+                &&  is_valid<decltype(make_getter(std::declval<T_second>(), std::declval<T_rest>()...))>::value
             >
         >
         {
@@ -194,18 +197,18 @@ namespace cppmp
                 first_getter_type   first;
                 second_getter_type  second;
 
-                constexpr getter_chain(
+                inline getter_chain(
                     first_getter_type&&     p_first,
                     second_getter_type&&    p_second)
                     : first (std::move(p_first))
                     , second(std::move(p_second))
                     { }
 
-                constexpr getter_chain(getter_chain&&) = default;
-                constexpr getter_chain(const getter_chain&) = default;
+                inline getter_chain(getter_chain&&) = default;
+                inline getter_chain(const getter_chain&) = default;
 
-                constexpr getter_chain& operator = (getter_chain&&) = default;
-                constexpr getter_chain& operator = (const getter_chain&) = default;
+                inline getter_chain& operator = (getter_chain&&) = default;
+                inline getter_chain& operator = (const getter_chain&) = default;
 
                 template<typename X_object>
                 constexpr decltype(auto) operator()(X_object&& obj) const
diff --git a/include/cppmp/misc/setter.h b/include/cppmp/misc/setter.h
index ab4a9f4..24e0333 100644
--- a/include/cppmp/misc/setter.h
+++ b/include/cppmp/misc/setter.h
@@ -28,11 +28,13 @@ namespace cppmp
     template<typename T>
     struct is_setter;
 
+    #ifdef cppmp_supports_variable_templates
     /**
      * @brief Is true if the passed type is an setter, false otherwise.
      */
     template<typename T>
     constexpr decltype(auto) is_setter_v = is_setter<T>::value;
+    #endif
 
     /**
      * @brief Predicate to create new setter objects.
diff --git a/include/cppmp/misc/setter.inl b/include/cppmp/misc/setter.inl
index c4ef1fc..fafdd76 100644
--- a/include/cppmp/misc/setter.inl
+++ b/include/cppmp/misc/setter.inl
@@ -27,7 +27,8 @@ namespace cppmp
         template<typename T_setter>
         struct setter_builder<
             list<T_setter>,
-            enable_if_t<is_setter_v<decay_t<T_setter>>>>
+            enable_if_t<is_setter<decay_t<T_setter>>::value
+        >>
         {
             static constexpr decltype(auto) apply(T_setter&& setter)
                 { return std::forward<T_setter>(setter); }
@@ -50,15 +51,15 @@ namespace cppmp
 
                 member_type member;
 
-                constexpr setter_member_var(member_type p_member)
+                inline setter_member_var(member_type p_member)
                     : member(p_member)
                     { }
 
-                constexpr setter_member_var(setter_member_var&&) = default;
-                constexpr setter_member_var(const setter_member_var&) = default;
+                inline setter_member_var(setter_member_var&&) = default;
+                inline setter_member_var(const setter_member_var&) = default;
 
-                constexpr setter_member_var& operator = (setter_member_var&&) = default;
-                constexpr setter_member_var& operator = (const setter_member_var&) = default;
+                inline setter_member_var& operator = (setter_member_var&&) = default;
+                inline setter_member_var& operator = (const setter_member_var&) = default;
 
                 template<typename X_object, typename X_value>
                 constexpr void operator()(X_object&& obj, X_value&& value) const
@@ -88,15 +89,15 @@ namespace cppmp
 
                 member_type member;
 
-                constexpr setter_member_func(member_type p_member)
+                inline setter_member_func(member_type p_member)
                     : member(p_member)
                     { }
 
-                constexpr setter_member_func(setter_member_func&&) = default;
-                constexpr setter_member_func(const setter_member_func&) = default;
+                inline setter_member_func(setter_member_func&&) = default;
+                inline setter_member_func(const setter_member_func&) = default;
 
-                constexpr setter_member_func& operator = (setter_member_func&&) = default;
-                constexpr setter_member_func& operator = (const setter_member_func&) = default;
+                inline setter_member_func& operator = (setter_member_func&&) = default;
+                inline setter_member_func& operator = (const setter_member_func&) = default;
 
                 template<typename X_object, typename X_value>
                 constexpr void operator()(X_object&& obj, X_value&& value) const
@@ -131,7 +132,7 @@ namespace cppmp
         struct setter_builder<
             list<T_lambda>,
             enable_if_t<
-                    is_valid_v<lambda_traits<decay_t<T_lambda>>>
+                    is_valid<lambda_traits<decay_t<T_lambda>>>::value
                 &&  lambda_traits<decay_t<T_lambda>>::argument_count_v == 2>>
         {
             struct setter_lambda
@@ -145,15 +146,15 @@ namespace cppmp
 
                 lambda_type lambda;
 
-                constexpr setter_lambda(lambda_type&& p_lambda)
+                inline cppmp_constexpr_lambda setter_lambda(lambda_type&& p_lambda)
                     : lambda(std::forward<lambda_type>(p_lambda))
                     { }
 
-                constexpr setter_lambda(setter_lambda&&) = default;
-                constexpr setter_lambda(const setter_lambda&) = default;
+                inline cppmp_constexpr_lambda setter_lambda(setter_lambda&&) = default;
+                inline cppmp_constexpr_lambda setter_lambda(const setter_lambda&) = default;
 
-                constexpr setter_lambda& operator = (setter_lambda&&) = default;
-                constexpr setter_lambda& operator = (const setter_lambda&) = default;
+                inline cppmp_constexpr_lambda setter_lambda& operator = (setter_lambda&&) = default;
+                inline cppmp_constexpr_lambda setter_lambda& operator = (const setter_lambda&) = default;
 
                 template<typename X_object, typename X_value>
                 constexpr void operator()(X_object&& obj, X_value&& value) const
diff --git a/include/cppmp/traits/lambda_traits.inl b/include/cppmp/traits/lambda_traits.inl
index ea1d1d6..8d71af2 100644
--- a/include/cppmp/traits/lambda_traits.inl
+++ b/include/cppmp/traits/lambda_traits.inl
@@ -42,7 +42,11 @@ namespace cppmp
     /* lambda_traits */
 
     template<typename T_lambda>
-    struct lambda_traits<T_lambda, enable_if_t<is_valid_v<decltype(&T_lambda::operator())>>>
+    struct lambda_traits<
+        T_lambda,
+        enable_if_t<
+            is_valid<decltype(&T_lambda::operator())>::value
+        >>
         : public lambda_traits<decltype(&T_lambda::operator())>
         { };
 
diff --git a/test/cppmp/cppmp_checker_tests.cpp b/test/cppmp/cppmp_checker_tests.cpp
new file mode 100644
index 0000000..bcda3f4
--- /dev/null
+++ b/test/cppmp/cppmp_checker_tests.cpp
@@ -0,0 +1,26 @@
+#include <cppmp/core/checker.h>
+
+template<typename X, typename = void>
+struct tpl;
+
+template<>
+struct tpl<char, void>
+{
+    using is_default = cppmp::true_t;
+};
+
+template<>
+struct tpl<int, void>
+    { };
+
+static_assert(
+    cppmp::is_valid<void>::value,
+    "Expected is_valid to be true");
+
+static_assert(
+    cppmp::is_valid<tpl<int>>::value,
+    "Expected is_valid to be true");
+
+static_assert(
+    !cppmp::is_valid<tpl<float>>::value,
+    "Expected is_valid to be false");
diff --git a/test/cppmp/cppmp_generic_predicate_tests.cpp b/test/cppmp/cppmp_generic_predicate_tests.cpp
new file mode 100644
index 0000000..12fdd55
--- /dev/null
+++ b/test/cppmp/cppmp_generic_predicate_tests.cpp
@@ -0,0 +1,39 @@
+#include <gtest/gtest.h>
+
+#include <cppmp/misc/generic_predicate.h>
+
+template<typename X, typename = void>
+struct builder
+{
+    using is_default = cppmp::true_t;
+
+    template<typename... T_args>
+    static constexpr decltype(auto) apply(T_args&&...)
+        { static_assert(sizeof...(T_args) == -1, "Invalid parameters for build(...)!"); }
+};
+
+template<>
+struct builder<
+    cppmp::list<int>,
+    void>
+{
+    static constexpr decltype(auto) apply(int i)
+        { return i; }
+};
+
+constexpr decltype(auto) build = cppmp::generic_predicate<builder> { };
+
+static_assert(
+    !decltype(build)::is_valid<void>::value,
+    "Expected build to be invalid");
+
+static_assert(
+    decltype(build)::is_valid<int>::value,
+    "Expected build to be valid");
+
+TEST(generic_predicate_tests, simple)
+{
+    auto i = build(5);
+
+    EXPECT_EQ(5, i);
+}
diff --git a/test/cppmp/cppmp_getter_tests.cpp b/test/cppmp/cppmp_getter_tests.cpp
index cfa9302..3d935bb 100644
--- a/test/cppmp/cppmp_getter_tests.cpp
+++ b/test/cppmp/cppmp_getter_tests.cpp
@@ -24,8 +24,9 @@ TEST(cppmp_getter_tests, member_var)
     test_obj o { 1 };
 
     auto g = make_getter(&test_obj::value);
+    auto i = g(o);
 
-    EXPECT_EQ(1, g(o));
+    EXPECT_EQ(1, i);
 }
 
 TEST(cppmp_getter_tests, member_func)
@@ -33,8 +34,9 @@ TEST(cppmp_getter_tests, member_func)
     test_obj o { 1 };
 
     auto g = make_getter(&test_obj::get);
+    auto i = g(o);
 
-    EXPECT_EQ(1, g(o));
+    EXPECT_EQ(1, i);
 }
 
 TEST(cppmp_getter_tests, const_member_func)
@@ -42,8 +44,9 @@ TEST(cppmp_getter_tests, const_member_func)
     test_obj o { 1 };
 
     auto g = make_getter(&test_obj::cget);
+    auto i = g(o);
 
-    EXPECT_EQ(1, g(o));
+    EXPECT_EQ(1, i);
 }
 
 TEST(cppmp_getter_tests, static_func)
@@ -51,8 +54,9 @@ TEST(cppmp_getter_tests, static_func)
     test_obj o { 1 };
 
     auto g = make_getter(&test_obj::sget);
+    auto i = g(o);
 
-    EXPECT_EQ(1, g(o));
+    EXPECT_EQ(1, i);
 }
 
 TEST(cppmp_getter_tests, lambda)
@@ -62,6 +66,7 @@ TEST(cppmp_getter_tests, lambda)
     auto g = make_getter([](test_obj& o){
         return o.value;
     });
+    auto i = g(obj);
 
-    EXPECT_EQ(1, g(obj));
+    EXPECT_EQ(1, i);
 }
diff --git a/test/cppmp/cppmp_traits_test.cpp b/test/cppmp/cppmp_traits_test.cpp
index abe0f86..cd0a666 100644
--- a/test/cppmp/cppmp_traits_test.cpp
+++ b/test/cppmp/cppmp_traits_test.cpp
@@ -27,45 +27,45 @@ using type3 = ::cppmp::lambda_traits<std::string(*)(bool)>;
 using type4 = ::cppmp::lambda_traits<decltype(cpp_traits_lambda)>;
 using type5 = ::cppmp::lambda_traits<decltype(&static_fuu)>;
 
-static_assert(is_same_v<typename type0::object_type,            test_obj>,                          "");
-static_assert(is_same_v<typename type0::return_type,            int>,                               "");
-static_assert(is_same_v<typename type0::arguments_type,         std::tuple<int>>,                   "");
-static_assert(                   type0::is_mutable_v     ==     true,                               "");
-static_assert(                   type0::is_static_v      ==     false,                              "");
-static_assert(                   type0::argument_count_v ==     1,                                  "");
+static_assert(is_same<typename type0::object_type,            test_obj>::value,                         "");
+static_assert(is_same<typename type0::return_type,            int>::value,                              "");
+static_assert(is_same<typename type0::arguments_type,         std::tuple<int>>::value,                  "");
+static_assert(                 type0::is_mutable_v     ==     true,                                     "");
+static_assert(                 type0::is_static_v      ==     false,                                    "");
+static_assert(                 type0::argument_count_v ==     1,                                        "");
 
-static_assert(is_same_v<typename type1::object_type,            const test_obj>,                    "");
-static_assert(is_same_v<typename type1::return_type,            double>,                            "");
-static_assert(is_same_v<typename type1::arguments_type,         std::tuple<float, std::string>>,    "");
-static_assert(                   type1::is_mutable_v     ==     false,                              "");
-static_assert(                   type1::is_static_v      ==     false,                              "");
-static_assert(                   type1::argument_count_v ==     2,                                  "");
+static_assert(is_same<typename type1::object_type,            const test_obj>::value,                   "");
+static_assert(is_same<typename type1::return_type,            double>::value,                           "");
+static_assert(is_same<typename type1::arguments_type,         std::tuple<float, std::string>>::value,   "");
+static_assert(                 type1::is_mutable_v     ==     false,                                    "");
+static_assert(                 type1::is_static_v      ==     false,                                    "");
+static_assert(                 type1::argument_count_v ==     2,                                        "");
 
-static_assert(is_same_v<typename type2::object_type,            void>,                              "");
-static_assert(is_same_v<typename type2::return_type,            std::string>,                       "");
-static_assert(is_same_v<typename type2::arguments_type,         std::tuple<>>,                      "");
-static_assert(                   type2::is_mutable_v     ==     false,                              "");
-static_assert(                   type2::is_static_v      ==     true,                               "");
-static_assert(                   type2::argument_count_v ==     0,                                  "");
+static_assert(is_same<typename type2::object_type,            void>::value,                             "");
+static_assert(is_same<typename type2::return_type,            std::string>::value,                      "");
+static_assert(is_same<typename type2::arguments_type,         std::tuple<>>::value,                     "");
+static_assert(                 type2::is_mutable_v     ==     false,                                    "");
+static_assert(                 type2::is_static_v      ==     true,                                     "");
+static_assert(                 type2::argument_count_v ==     0,                                        "");
 
-static_assert(is_same_v<typename type3::object_type,            void>,                              "");
-static_assert(is_same_v<typename type3::return_type,            std::string>,                       "");
-static_assert(is_same_v<typename type3::arguments_type,         std::tuple<bool>>,                  "");
-static_assert(                   type3::is_mutable_v     ==     false,                              "");
-static_assert(                   type3::is_static_v      ==     true,                               "");
-static_assert(                   type3::argument_count_v ==     1,                                  "");
+static_assert(is_same<typename type3::object_type,            void>::value,                             "");
+static_assert(is_same<typename type3::return_type,            std::string>::value,                      "");
+static_assert(is_same<typename type3::arguments_type,         std::tuple<bool>>::value,                 "");
+static_assert(                 type3::is_mutable_v     ==     false,                                    "");
+static_assert(                 type3::is_static_v      ==     true,                                     "");
+static_assert(                 type3::argument_count_v ==     1,                                        "");
 
-static_assert(is_same_v<typename type4::return_type,            bool>,                              "");
-static_assert(is_same_v<typename type4::arguments_type,         std::tuple<std::string, int>>,      "");
-static_assert(                   type4::is_mutable_v     ==     false,                              "");
-static_assert(                   type4::is_static_v      ==     false,                              "");
-static_assert(                   type4::argument_count_v ==     2,                                  "");
+static_assert(is_same<typename type4::return_type,            bool>::value,                             "");
+static_assert(is_same<typename type4::arguments_type,         std::tuple<std::string, int>>::value,     "");
+static_assert(                 type4::is_mutable_v     ==     false,                                    "");
+static_assert(                 type4::is_static_v      ==     false,                                    "");
+static_assert(                 type4::argument_count_v ==     2,                                        "");
 
-static_assert(is_same_v<typename type5::return_type,            const test_obj&>,                   "");
-static_assert(is_same_v<typename type5::arguments_type,         std::tuple<>>,                      "");
-static_assert(                   type5::is_mutable_v     ==     false,                              "");
-static_assert(                   type5::is_static_v      ==     true,                               "");
-static_assert(                   type5::argument_count_v ==     0,                                  "");
+static_assert(is_same<typename type5::return_type,            const test_obj&>::value,                  "");
+static_assert(is_same<typename type5::arguments_type,         std::tuple<>>::value,                     "");
+static_assert(                 type5::is_mutable_v     ==     false,                                    "");
+static_assert(                 type5::is_static_v      ==     true,                                     "");
+static_assert(                 type5::argument_count_v ==     0,                                        "");
 
 TEST(cppmp_traits_test, dummy)
 {