More uses of standard type traits aliases

src/commands.cc

@@ -69,7 +69,7 @@ struct PerArgumentCommandCompleter<Completer, Rest...> : PerArgumentCommandCompl
 {
     template<typename C, typename... R,
              typename = typename std::enable_if<not std::is_base_of<PerArgumentCommandCompleter<>,
-                                                typename std::remove_reference<C>::type>::value>::type>
+                                                std::remove_reference_t<C>>::value>::type>
     PerArgumentCommandCompleter(C&& completer, R&&... rest)
       : PerArgumentCommandCompleter<Rest...>(std::forward<R>(rest)...),
         m_completer(std::forward<C>(completer)) {}
@@ -93,7 +93,7 @@ struct PerArgumentCommandCompleter<Completer, Rest...> : PerArgumentCommandCompl
 };
 
 template<typename... Completers>
-PerArgumentCommandCompleter<typename std::decay<Completers>::type...>
+PerArgumentCommandCompleter<std::decay_t<Completers>...>
 make_completer(Completers&&... completers)
 {
     return {std::forward<Completers>(completers)...};

src/containers.hh

@@ -29,13 +29,10 @@ struct ReverseView
     Container m_container;
 };
 
-template<typename C>
-using RemoveReference = typename std::remove_reference<C>::type;
-
 struct ReverseFactory
 {
     template<typename Container>
-    ReverseView<RemoveReference<Container>> operator()(Container&& container) const
+    ReverseView<std::remove_reference_t<Container>> operator()(Container&& container) const
     {
         return {std::move(container)};
     }
@@ -111,7 +108,7 @@ struct FilterFactory
     FilterView<Container&, Filter> operator()(Container& container) const { return {container, std::move(m_filter)}; }
 
     template<typename Container>
-    FilterView<RemoveReference<Container>, Filter> operator()(Container&& container) const { return {std::move(container), std::move(m_filter)}; }
+    FilterView<std::remove_reference_t<Container>, Filter> operator()(Container&& container) const { return {std::move(container), std::move(m_filter)}; }
 
     Filter m_filter;
 };
@@ -165,7 +162,7 @@ struct TransformFactory
     TransformView<Container&, Transform> operator()(Container& container) const { return {container, std::move(m_transform)}; }
 
     template<typename Container>
-    TransformView<RemoveReference<Container>, Transform> operator()(Container&& container) const { return {std::move(container), std::move(m_transform)}; }
+    TransformView<std::remove_reference_t<Container>, Transform> operator()(Container&& container) const { return {std::move(container), std::move(m_transform)}; }
 
     Transform m_transform;
 };
@@ -178,9 +175,9 @@ template<typename Container, typename Separator = ValueOf<Container>,
 struct SplitView
 {
     using ContainerIt = IteratorOf<Container>;
-    using ValueType = typename std::conditional<std::is_same<void, ValueTypeParam>::value,
-                                                std::pair<IteratorOf<Container>, IteratorOf<Container>>,
-                                                ValueTypeParam>::type;
+    using ValueType = std::conditional_t<std::is_same<void, ValueTypeParam>::value,
+                                         std::pair<IteratorOf<Container>, IteratorOf<Container>>,
+                                         ValueTypeParam>;
 
     struct Iterator : std::iterator<std::forward_iterator_tag, ValueType>
     {
@@ -233,7 +230,7 @@ template<typename ValueType, typename Separator>
 struct SplitViewFactory
 {
     template<typename Container>
-    SplitView<RemoveReference<Container>, Separator, ValueType>
+    SplitView<std::remove_reference_t<Container>, Separator, ValueType>
     operator()(Container&& container) const { return {std::move(container), std::move(separator)}; }
 
     template<typename Container>
@@ -251,8 +248,8 @@ struct ConcatView
 {
     using ContainerIt1 = decltype(begin(std::declval<Container1>()));
     using ContainerIt2 = decltype(begin(std::declval<Container2>()));
-    using ValueType = typename std::common_type<typename std::iterator_traits<ContainerIt1>::value_type,
-                                                typename std::iterator_traits<ContainerIt2>::value_type>::type;
+    using ValueType = typename std::common_type_t<typename std::iterator_traits<ContainerIt1>::value_type,
+                                                  typename std::iterator_traits<ContainerIt2>::value_type>;
 
     struct Iterator : std::iterator<std::forward_iterator_tag, ValueType>
     {

src/hash.hh

@@ -65,6 +65,9 @@ struct HashCompatible : std::false_type {};
 
 template<typename T> struct HashCompatible<T, T> : std::true_type {};
 
+template<typename Lhs, typename Rhs>
+constexpr bool IsHashCompatible = HashCompatible<Lhs, Rhs>::value;
+
 }
 
 #endif // hash_hh_INCLUDED

src/hash_map.hh

@@ -155,9 +155,9 @@ struct HashMap
     }
 
     template<typename KeyType>
-    using EnableIfHashCompatible = typename std::enable_if<
-        HashCompatible<Key, typename std::decay<KeyType>::type>::value
-    >::type;
+    using EnableIfHashCompatible = std::enable_if_t<
+        IsHashCompatible<Key, std::decay_t<KeyType>>
+    >;
 
     template<typename KeyType, typename = EnableIfHashCompatible<KeyType>>
     int find_index(const KeyType& key, size_t hash) const

src/option_types.hh

@@ -24,7 +24,7 @@ constexpr decltype(T::option_type_name) option_type_name(Meta::Type<T>)
 }
 
 template<typename Enum>
-typename std::enable_if<std::is_enum<Enum>::value, String>::type
+std::enable_if_t<std::is_enum<Enum>::value, String>
 option_type_name(Meta::Type<Enum>)
 {
     return format("{}({})", with_bit_ops(Meta::Type<Enum>{}) ? "flags" : "enum",