1 files changed, 77 insertions, 0 deletions
diff --git a/include/unicode/type_traits.h b/include/unicode/type_traits.h
new file mode 100644
index 0000000..3ee1d82
--- /dev/null
+++ b/include/unicode/type_traits.h
@@ -0,0 +1,77 @@
+#pragma once
+
+#include "utf.h"
+
+#include <string>
+#include <type_traits>
+
+namespace unicode {
+
+ using namespace detail;
+
+ // helper traits
+ 
+ template<typename T>
+ struct is_encoding
+ {
+  static const bool value{std::is_empty_v<T>};
+ };
+ 
+ template<typename T>
+ inline constexpr bool is_encoding_v {is_encoding<T>::value};
+
+ template<typename T>
+ struct is_container
+ {
+  static const bool value{!std::is_empty_v<T>};
+ };
+ 
+ template<typename T>
+ inline constexpr bool is_container_v {is_container<T>::value};
+
+ template<typename T>
+ struct is_char
+ {
+  static const bool value{std::is_trivial_v<T> && std::is_scalar_v<T> && !std::is_empty_v<T>};
+ };
+ 
+ template<typename T>
+ inline constexpr bool is_char_v {is_char<T>::value};
+
+ template<typename T>
+ struct is_utf_encoding
+ {
+  static const bool value{std::is_same_v<T, UTF<utf_iterator<typename T::value_type>, utf_back_insert_iterator<typename T::value_type>>>};
+ };
+
+ template<typename T>
+ inline constexpr bool is_utf_encoding_v {is_utf_encoding<T>::value};
+
+ template<typename T>
+ struct is_utf_8
+ {
+  static const bool value{std::is_trivial_v<T> && sizeof(T) == 1};
+ };
+ 
+ template<typename T>
+ inline constexpr bool is_utf_8_v {is_utf_8<T>::value};
+
+ template<typename T>
+ struct is_utf_16
+ {
+  static const bool value{std::is_trivial_v<T> && sizeof(T) == 2};
+ };
+ 
+ template<typename T>
+ inline constexpr bool is_utf_16_v {is_utf_16<T>::value};
+
+ template<typename T>
+ struct is_utf_32
+ {
+  static const bool value{std::is_trivial_v<T> && sizeof(T) == 4};
+ };
+ 
+ template<typename T>
+ inline constexpr bool is_utf_32_v {is_utf_32<T>::value};
+
+} // namespace unicode