diff --git a/include/iris/string.hpp b/include/iris/string.hpp
index 694720e..3b10ab3 100644
--- a/include/iris/string.hpp
+++ b/include/iris/string.hpp
@@ -6,18 +6,20 @@
 #include <iris/config.hpp> // IWYU pragma: keep
 
 #include <concepts>
-#include <string>
-#include <string_view>
+#include <type_traits>
+#include <utility>
+#include <string> // IWYU pragma: export
+#include <string_view> // IWYU pragma: export
 
 namespace iris {
 
 template<class T>
 concept CharLike =
-    std::same_as<T, char> ||
-    std::same_as<T, char32_t> ||
-    std::same_as<T, wchar_t> ||
-    std::same_as<T, char8_t> ||
-    std::same_as<T, char16_t>;
+    std::same_as<std::remove_cv_t<T>, char> ||
+    std::same_as<std::remove_cv_t<T>, char32_t> ||
+    std::same_as<std::remove_cv_t<T>, wchar_t> ||
+    std::same_as<std::remove_cv_t<T>, char8_t> ||
+    std::same_as<std::remove_cv_t<T>, char16_t>;
 
 template<class T>
 concept StringLike =
@@ -30,6 +32,26 @@ concept StringLike =
 template<class T>
 concept NotStringLike = !StringLike<T>;
 
+
+namespace detail {
+
+template<class T>
+struct char_type_for_impl
+{
+    using type = decltype(std::basic_string_view{std::declval<T>()})::value_type;
+};
+
+template<CharLike CharT>
+struct char_type_for_impl<CharT>
+{
+    using type = std::remove_cv_t<CharT>;
+};
+
+} // detail
+
+template<class T>
+using char_type_for = detail::char_type_for_impl<T>::type;
+
 } // iris
 
 #endif
diff --git a/test/string_algo.cpp b/test/string_algo.cpp
index a54a016..3a64898 100644
--- a/test/string_algo.cpp
+++ b/test/string_algo.cpp
@@ -1,5 +1,6 @@
 #include "iris_test.hpp"
 
+#include <iris/string.hpp>
 #include <iris/string_algo.hpp>
 
 #include <format>
@@ -14,6 +15,77 @@ using namespace std::string_view_literals;
 
 // NOLINTBEGIN(readability-container-size-empty)
 
+TEST_CASE("string: type traits")
+{
+    STATIC_CHECK(iris::CharLike<char>);
+    STATIC_CHECK(iris::CharLike<wchar_t>);
+    STATIC_CHECK(iris::CharLike<char8_t>);
+    STATIC_CHECK(iris::CharLike<char16_t>);
+    STATIC_CHECK(iris::CharLike<char32_t>);
+
+    STATIC_CHECK(iris::CharLike<char const>);
+    STATIC_CHECK(iris::CharLike<char volatile>);
+    STATIC_CHECK(iris::CharLike<char const volatile>);
+    STATIC_CHECK(!iris::CharLike<char const&>);
+    STATIC_CHECK(!iris::CharLike<char&>);
+
+    STATIC_CHECK(std::same_as<iris::char_type_for<char>, char>);
+    STATIC_CHECK(std::same_as<iris::char_type_for<char const>, char>);
+    STATIC_CHECK(std::same_as<iris::char_type_for<char volatile>, char>);
+    STATIC_CHECK(std::same_as<iris::char_type_for<char const volatile>, char>);
+
+    STATIC_CHECK(std::same_as<iris::char_type_for<char*>, char>);
+    STATIC_CHECK(std::same_as<iris::char_type_for<char const*>, char>);
+
+#define IRIS_CHECK_STRING_LIKE(CharT, type) \
+    STATIC_CHECK(iris::StringLike<type>); \
+    STATIC_CHECK(std::same_as<iris::char_type_for<type>, CharT>);
+
+    IRIS_CHECK_STRING_LIKE(char, char const*);
+    IRIS_CHECK_STRING_LIKE(char, char const* const);
+    IRIS_CHECK_STRING_LIKE(char, char const*&);
+    IRIS_CHECK_STRING_LIKE(char, char const* const&);
+    IRIS_CHECK_STRING_LIKE(char, char const*&&);
+    IRIS_CHECK_STRING_LIKE(char, char const* const&&);
+
+    IRIS_CHECK_STRING_LIKE(char, std::string_view);
+    IRIS_CHECK_STRING_LIKE(char, std::string_view const);
+    IRIS_CHECK_STRING_LIKE(char, std::string_view&);
+    IRIS_CHECK_STRING_LIKE(char, std::string_view const&);
+    IRIS_CHECK_STRING_LIKE(char, std::string_view&&);
+    IRIS_CHECK_STRING_LIKE(char, std::string_view const&&);
+
+    IRIS_CHECK_STRING_LIKE(char, std::string);
+    IRIS_CHECK_STRING_LIKE(char, std::string const);
+    IRIS_CHECK_STRING_LIKE(char, std::string&);
+    IRIS_CHECK_STRING_LIKE(char, std::string const&);
+    IRIS_CHECK_STRING_LIKE(char, std::string&&);
+    IRIS_CHECK_STRING_LIKE(char, std::string const&&);
+
+    IRIS_CHECK_STRING_LIKE(char32_t, char32_t const*);
+    IRIS_CHECK_STRING_LIKE(char32_t, char32_t const* const);
+    IRIS_CHECK_STRING_LIKE(char32_t, char32_t const*&);
+    IRIS_CHECK_STRING_LIKE(char32_t, char32_t const* const&);
+    IRIS_CHECK_STRING_LIKE(char32_t, char32_t const*&&);
+    IRIS_CHECK_STRING_LIKE(char32_t, char32_t const* const&&);
+
+    IRIS_CHECK_STRING_LIKE(char32_t, std::u32string_view);
+    IRIS_CHECK_STRING_LIKE(char32_t, std::u32string_view const);
+    IRIS_CHECK_STRING_LIKE(char32_t, std::u32string_view&);
+    IRIS_CHECK_STRING_LIKE(char32_t, std::u32string_view const&);
+    IRIS_CHECK_STRING_LIKE(char32_t, std::u32string_view&&);
+    IRIS_CHECK_STRING_LIKE(char32_t, std::u32string_view const&&);
+
+    IRIS_CHECK_STRING_LIKE(char32_t, std::u32string);
+    IRIS_CHECK_STRING_LIKE(char32_t, std::u32string const);
+    IRIS_CHECK_STRING_LIKE(char32_t, std::u32string&);
+    IRIS_CHECK_STRING_LIKE(char32_t, std::u32string const&);
+    IRIS_CHECK_STRING_LIKE(char32_t, std::u32string&&);
+    IRIS_CHECK_STRING_LIKE(char32_t, std::u32string const&&);
+
+#undef IRIS_CHECK_STRING_LIKE
+}
+
 TEST_CASE("string_algo: trim")
 {
 #ifdef _MSC_VER