diff --git a/doc/en/build.md b/doc/en/build.md
index 0b72578..2d555de 100644
--- a/doc/en/build.md
+++ b/doc/en/build.md
@@ -1,6 +1,6 @@
 # Building
 ## Prerequisites
-1. Compiler that supports C++20. Recommended compilers: `MSVC 19.3` (`Visual Studio 2022`) or higher, `GCC 12` or higher.
+1. Compiler that supports C++20. Recommended compilers: `MSVC 19.3` (`Visual Studio 2022`) or higher, `GCC 12` or higher, `Clang 14` or higher.
 2. `CMake`: `3.20` or higher.
 3. `GoogleTest` (optional): Only required when building unit tests.
 
diff --git a/doc/zh-CN/build.md b/doc/zh-CN/build.md
index c5a0586..aef4e38 100644
--- a/doc/zh-CN/build.md
+++ b/doc/zh-CN/build.md
@@ -1,6 +1,6 @@
 # 构建
 ## 前置要求
-1. 任意支持 C++20 的编译器，推荐：`MSVC 19.3`（`Visual Studio 2022`）或以上、`GCC 12` 或以上
+1. 任意支持 C++20 的编译器，推荐：`MSVC 19.3`（`Visual Studio 2022`）或以上、`GCC 12` 或以上、`Clang 14` 或以上
 2. `CMake`：`3.20` 或以上
 3. `GoogleTest` （可选）：仅构建单元测试时需要
 
diff --git a/example/info.cpp b/example/info.cpp
index 1b3ae94..f8622e8 100644
--- a/example/info.cpp
+++ b/example/info.cpp
@@ -15,6 +15,9 @@ int main()
 #ifdef PAPILIO_COMPILER_GCC
     println("PAPILIO_COMPILER_GCC = {}", PAPILIO_COMPILER_GCC);
 #endif
+#ifdef PAPILIO_COMPILER_CLANG
+    println("PAPILIO_COMPILER_CLANG = {}", PAPILIO_COMPILER_CLANG);
+#endif
 
 #ifdef PAPILIO_HAS_MULTIDIMENSIONAL_SUBSCRIPT
     println("PAPILIO_HAS_MULTIDIMENSIONAL_SUBSCRIPT = {:d}L", PAPILIO_HAS_MULTIDIMENSIONAL_SUBSCRIPT);
diff --git a/example/playground/ipapilio.hpp b/example/playground/ipapilio.hpp
index eb0414f..a4b5e93 100644
--- a/example/playground/ipapilio.hpp
+++ b/example/playground/ipapilio.hpp
@@ -27,6 +27,9 @@ class ipapilio
 
         std::string help;
         callback_t callback;
+
+        command_data(std::string h, callback_t cb)
+            : help(std::move(h)), callback(cb) {}
     };
 
     std::map<std::string, command_data, std::less<>> m_cmds;
diff --git a/include/papilio/access/tuple.hpp b/include/papilio/access/tuple.hpp
index 509a0b1..d9e5e90 100644
--- a/include/papilio/access/tuple.hpp
+++ b/include/papilio/access/tuple.hpp
@@ -21,7 +21,7 @@ struct tuple_accessor
     using format_arg_type = basic_format_arg<Context>;
 
     [[nodiscard]]
-    static consteval std::size_t size() noexcept
+    static constexpr std::size_t size() noexcept
     {
         return std::tuple_size_v<Tuple>;
     }
diff --git a/include/papilio/container.hpp b/include/papilio/container.hpp
index ea4653f..10d1724 100644
--- a/include/papilio/container.hpp
+++ b/include/papilio/container.hpp
@@ -47,8 +47,8 @@ class small_vector_base : public detail::small_vector_impl
     using difference_type = std::ptrdiff_t;
     using reference = value_type&;
     using const_reference = const value_type&;
-    using pointer = std::allocator_traits<Allocator>::pointer;
-    using const_pointer = std::allocator_traits<Allocator>::const_pointer;
+    using pointer = typename std::allocator_traits<Allocator>::pointer;
+    using const_pointer = typename std::allocator_traits<Allocator>::const_pointer;
     using iterator = pointer;
     using const_iterator = const_pointer;
     using reverse_iterator = std::reverse_iterator<iterator>;
@@ -250,12 +250,12 @@ class small_vector : public small_vector_base<T, Allocator>
     using difference_type = std::ptrdiff_t;
     using reference = value_type&;
     using const_reference = const value_type&;
-    using pointer = my_base::pointer;
-    using const_pointer = my_base::const_pointer;
-    using iterator = my_base::iterator;
-    using const_iterator = my_base::const_iterator;
-    using reverse_iterator = my_base::reverse_iterator;
-    using const_reverse_iterator = my_base::const_reverse_iterator;
+    using pointer = typename my_base::pointer;
+    using const_pointer = typename my_base::const_pointer;
+    using iterator = typename my_base::iterator;
+    using const_iterator = typename my_base::const_iterator;
+    using reverse_iterator = typename my_base::reverse_iterator;
+    using const_reverse_iterator = typename my_base::const_reverse_iterator;
 
     small_vector() noexcept(std::is_nothrow_default_constructible_v<Allocator>)
         : my_base(), m_data()
@@ -708,7 +708,6 @@ class small_vector : public small_vector_base<T, Allocator>
             PAPILIO_ASSERT(this->size() < this->capacity());
 
             size_type tmp_size = this->size();
-            size_type tmp_capacity = this->capacity();
             pointer tmp_ptr = std::allocator_traits<Allocator>::allocate(
                 getal(), tmp_size
             );
@@ -1169,8 +1168,8 @@ class fixed_flat_map : public detail::fixed_flat_map_impl
     using key_compare = Compare;
     using reference = value_type&;
     using const_reference = value_type&;
-    using iterator = underlying_type::iterator;
-    using const_iterator = underlying_type::const_iterator;
+    using iterator = typename underlying_type::iterator;
+    using const_iterator = typename  underlying_type::const_iterator;
 
     class value_compare :
         public detail::value_compare_base<key_compare, is_transparent_v<Compare>>
diff --git a/include/papilio/core.hpp b/include/papilio/core.hpp
index dcd4e73..f63d4fc 100755
--- a/include/papilio/core.hpp
+++ b/include/papilio/core.hpp
@@ -174,7 +174,7 @@ class basic_format_arg
     {
     public:
         using value_type = std::remove_cvref_t<T>;
-        using accessor_t = handle_impl<T>::accessor_t;
+        using accessor_t = typename handle_impl<T>::accessor_t;
 
         handle_impl_ptr(const T& val) noexcept
             : m_ptr(std::addressof(val), false) {}
@@ -235,7 +235,7 @@ class basic_format_arg
     {
     public:
         using value_type = std::remove_cvref_t<T>;
-        using accessor_t = handle_impl<T>::accessor_t;
+        using accessor_t = typename handle_impl<T>::accessor_t;
 
         template <typename Arg>
         requires std::is_constructible_v<T, Arg>
@@ -415,7 +415,7 @@ class basic_format_arg
         void construct_impl(Args&&... args)
         {
             static_assert(detail::use_handle<typename Impl::value_type, char_type>);
-            static_assert(sizeof(Impl) <= m_storage.size());
+            static_assert(sizeof(Impl) <= storage_size);
 
             new(ptr()) Impl(std::forward<Args>(args)...);
         }
@@ -806,7 +806,7 @@ namespace detail
             return idx.visit(
                 [this]<typename T>(const T& v) -> bool
                 {
-                    if constexpr(std::is_same_v<T, indexing_value_type::index_type>)
+                    if constexpr(std::is_same_v<T, typename indexing_value_type::index_type>)
                     {
                         if(v < 0)
                             return false;
@@ -912,7 +912,7 @@ class static_format_args final : public detail::format_args_base<Context, CharT>
     using my_base::get;
 
     [[nodiscard]]
-    bool check(string_view_type key) const noexcept
+    bool check(string_view_type key) const noexcept override
     {
         return m_named_args.contains(key);
     }
@@ -1394,7 +1394,7 @@ class basic_format_parse_context
     using string_type = std::basic_string<char_type>;
     using string_view_type = std::basic_string_view<char_type>;
     using string_ref_type = utf::basic_string_ref<char_type>;
-    using const_iterator = string_ref_type::const_iterator;
+    using const_iterator = typename string_ref_type::const_iterator;
     using iterator = const_iterator;
     using size_type = std::size_t;
     using format_context_type = FormatContext;
@@ -1499,13 +1499,19 @@ namespace detail
 {
     // clang-format off
 
-    template <typename T, typename Context, typename Formatter = Context::template formatter_type<std::remove_const_t<T>>>
+    template <
+        typename T,
+        typename Context,
+        typename Formatter = typename Context::template formatter_type<std::remove_const_t<T>>>
     concept formattable_with_impl =
         std::semiregular<Formatter> &&
-        requires(Formatter& f, const Formatter& cf, T&& val, Context fmt_ctx, basic_format_parse_context<Context> parse_ctx)
-        {
-            { f.parse(parse_ctx) } -> std::same_as<typename decltype(parse_ctx)::iterator>;
-            { cf.format(val, fmt_ctx) } -> std::same_as<typename Context::iterator>;
+        requires(Formatter& f, const Formatter& cf, T&& val, Context fmt_ctx, basic_format_parse_context<Context> parse_ctx) {
+            {
+                f.parse(parse_ctx)
+            } -> std::same_as<typename decltype(parse_ctx)::iterator>;
+            {
+                cf.format(val, fmt_ctx)
+            } -> std::same_as<typename Context::iterator>;
         };
 
     // clang-format on
diff --git a/include/papilio/core.inl b/include/papilio/core.inl
index f08c185..4e5e113 100644
--- a/include/papilio/core.inl
+++ b/include/papilio/core.inl
@@ -15,7 +15,7 @@ void basic_format_arg<Context>::handle_impl_ptr<T>::format(parse_context& parse_
 {
     if constexpr(formattable_with<value_type, Context>)
     {
-        using formatter_t = Context::template formatter_type<value_type>;
+        using formatter_t = typename Context::template formatter_type<value_type>;
         formatter_t fmt;
         parse_ctx.advance_to(fmt.parse(parse_ctx));
 
@@ -34,7 +34,7 @@ void basic_format_arg<Context>::handle_impl_soo<T>::format(parse_context& parse_
 {
     if constexpr(formattable_with<value_type, Context>)
     {
-        using formatter_t = Context::template formatter_type<value_type>;
+        using formatter_t = typename Context::template formatter_type<value_type>;
         formatter_t fmt;
         parse_ctx.advance_to(fmt.parse(parse_ctx));
 
@@ -77,7 +77,7 @@ void basic_format_arg<Context>::format(parse_context& parse_ctx, Context& out_ct
             }
             else if constexpr(formattable_with<T, Context>)
             {
-                using formatter_t =  Context::template formatter_type<T>;
+                using formatter_t = typename Context::template formatter_type<T>;
                 formatter_t fmt;
                 parse_ctx.advance_to(fmt.parse(parse_ctx));
 
diff --git a/include/papilio/detail/compat.hpp b/include/papilio/detail/compat.hpp
index 152afdf..38d1d75 100644
--- a/include/papilio/detail/compat.hpp
+++ b/include/papilio/detail/compat.hpp
@@ -13,17 +13,14 @@ inline void unreachable()
     std::unreachable();
 #elif defined PAPILIO_COMPILER_MSVC
     __assume(false);
-#elif defined PAPILIO_COMPILER_GCC
+#elif defined PAPILIO_COMPILER_GCC || defined PAPILIO_COMPILER_CLANG
     __builtin_unreachable();
-
-    // TODO: Clang support
-
 #else
     // An empty function body and the [[noreturn]] attribute is enough to raise undefined behavior.
 #endif
 }
 
-// forwark_like<T, U> of C++ 23
+// forward_like<T, U> of C++ 23
 // Use implementation from cppreference.com
 PAPILIO_EXPORT template <class T, class U>
 [[nodiscard]]
diff --git a/include/papilio/macros.hpp b/include/papilio/macros.hpp
index 25a91fc..a2f3949 100644
--- a/include/papilio/macros.hpp
+++ b/include/papilio/macros.hpp
@@ -21,11 +21,13 @@
 #    define PAPILIO_COMPILER_MSVC _MSC_VER
 #endif
 #ifdef __GNUC__
-#    define PAPILIO_COMPILER_GCC __GNUC__
+#    ifndef __clang__
+#        define PAPILIO_COMPILER_GCC __GNUC__
+#    else
+#        define PAPILIO_COMPILER_CLANG __clang_major__
+#    endif
 #endif
 
-// TODO: Clang support
-
 #define PAPILIO_ASSERT(expr) assert(expr)
 
 #if defined(_WIN32) || defined(_WIN64)
diff --git a/include/papilio/script/interpreter.hpp b/include/papilio/script/interpreter.hpp
index 19ad9ce..6c08a6b 100644
--- a/include/papilio/script/interpreter.hpp
+++ b/include/papilio/script/interpreter.hpp
@@ -708,7 +708,7 @@ class basic_interpreter_base : public script_base
 
         if constexpr(char8_like<char_type>)
         {
-            auto result = std::from_chars(
+            std::from_chars(
                 std::bit_cast<const char_type*>(start.base()),
                 std::bit_cast<const char_type*>(stop.base()),
                 val
@@ -717,7 +717,7 @@ class basic_interpreter_base : public script_base
         else
         {
             std::string tmp = string_ref_type(start, stop).to_string();
-            auto result = std::from_chars(
+            std::from_chars(
                 std::to_address(tmp.begin()),
                 std::to_address(tmp.end()),
                 val
@@ -895,7 +895,7 @@ class basic_interpreter :
 
     using parse_context = basic_format_parse_context<FormatContext>;
 
-    using iterator = my_base::iterator;
+    using iterator = typename my_base::iterator;
     static_assert(std::is_same_v<iterator, typename parse_context::iterator>);
 
     basic_interpreter() = default;
@@ -1111,7 +1111,7 @@ class basic_interpreter :
             }
             else
             {
-                using int_t = variable_type::int_type;
+                using int_t = typename variable_type::int_type;
                 int_t val = my_base::template parse_integer<int_t>(start, int_end).first;
 
                 return std::make_pair(val, int_end);
diff --git a/include/papilio/utf/codepoint.hpp b/include/papilio/utf/codepoint.hpp
index bad05d9..f7a1768 100644
--- a/include/papilio/utf/codepoint.hpp
+++ b/include/papilio/utf/codepoint.hpp
@@ -228,6 +228,8 @@ PAPILIO_EXPORT class codepoint
         return *this;
     }
 
+    constexpr codepoint& operator=(const codepoint&) noexcept = default;
+
     constexpr void clear() noexcept
     {
         m_data[0] = 0;
diff --git a/include/papilio/utf/string.hpp b/include/papilio/utf/string.hpp
index a31edad..f65dab1 100644
--- a/include/papilio/utf/string.hpp
+++ b/include/papilio/utf/string.hpp
@@ -40,6 +40,8 @@ namespace detail
         constexpr const_str_iter_impl() noexcept = default;
         constexpr const_str_iter_impl(const const_str_iter_impl&) noexcept = default;
 
+        constexpr const_str_iter_impl& operator=(const const_str_iter_impl&) noexcept = default;
+
     protected:
         constexpr const_str_iter_impl(string_view_type str, size_type offset, std::uint8_t len) noexcept
             : m_str(str), m_offset(offset), m_len(len) {}
@@ -150,6 +152,8 @@ namespace detail
         constexpr const_str_iter_impl() noexcept = default;
         constexpr const_str_iter_impl(const const_str_iter_impl&) noexcept = default;
 
+        constexpr const_str_iter_impl& operator=(const const_str_iter_impl&) noexcept = default;
+
     protected:
         constexpr const_str_iter_impl(string_view_type str, size_type offset, std::uint8_t len) noexcept
             : m_str(str), m_offset(offset), m_len(len) {}
@@ -238,8 +242,13 @@ namespace detail
         constexpr const_str_iter_impl() noexcept = default;
         constexpr const_str_iter_impl(const const_str_iter_impl&) noexcept = default;
 
+        constexpr const_str_iter_impl& operator=(const const_str_iter_impl&) noexcept = default;
+
+    private:
+        using base_iter_t = typename string_view_type::const_iterator;
+
     protected:
-        constexpr const_str_iter_impl(string_view_type::const_iterator iter) noexcept
+        constexpr const_str_iter_impl(base_iter_t iter) noexcept
             : m_iter(iter) {}
 
         constexpr void next() noexcept
@@ -288,7 +297,7 @@ namespace detail
         }
 
     private:
-        string_view_type::const_iterator m_iter;
+        base_iter_t m_iter;
     };
 
     class str_static_base
@@ -833,9 +842,9 @@ class basic_string_ref<CharT> : public detail::str_base<CharT, basic_string_ref<
     using string_type = std::basic_string<CharT>;
     using string_view_type = std::basic_string_view<CharT>;
 
-    using const_iterator = my_base::const_iterator;
+    using const_iterator = typename my_base::const_iterator;
     using iterator = const_iterator;
-    using const_reverse_iterator = my_base::const_reverse_iterator;
+    using const_reverse_iterator = typename my_base::const_reverse_iterator;
     using reverse_iterator = const_reverse_iterator;
 
     constexpr basic_string_ref() noexcept = default;
@@ -1260,8 +1269,8 @@ class basic_string_container<CharT> : public detail::str_base<CharT, basic_strin
     using string_type = std::basic_string<CharT>;
     using string_ref_type = basic_string_ref<CharT>;
 
-    using const_iterator = my_base::const_iterator;
-    using const_reverse_iterator = my_base::const_reverse_iterator;
+    using const_iterator = typename my_base::const_iterator;
+    using const_reverse_iterator = typename my_base::const_reverse_iterator;
 
     basic_string_container() noexcept = default;
     basic_string_container(std::nullptr_t) = delete;
diff --git a/include/papilio/utility.hpp b/include/papilio/utility.hpp
index fcf1654..1cba866 100644
--- a/include/papilio/utility.hpp
+++ b/include/papilio/utility.hpp
@@ -302,7 +302,9 @@ inline namespace literals
 
 PAPILIO_EXPORT template <typename T>
 struct independent_proxy : public std::reference_wrapper<T>
-{};
+{
+    using std::reference_wrapper<T>::reference_wrapper;
+};
 
 PAPILIO_EXPORT struct independent_t
 {
@@ -623,7 +625,7 @@ namespace detail
             return *this;
         }
 
-        constexpr void swap(compressed_pair_impl& other) noexcept
+        constexpr void swap(compressed_pair_impl&) noexcept
         {
             // empty
         }
@@ -698,8 +700,8 @@ class basic_iterbuf :
 public:
     using char_type = CharT;
     using iterator = Iterator;
-    using int_type = base::int_type;
-    using traits_type = base::traits_type;
+    using int_type = typename base::int_type;
+    using traits_type = typename base::traits_type;
 
     basic_iterbuf() = default;
 
diff --git a/test/test_format.cpp b/test/test_format.cpp
index bc02678..c6ca2d8 100644
--- a/test/test_format.cpp
+++ b/test/test_format.cpp
@@ -139,7 +139,7 @@ class yes_no_numpunct : public std::numpunct<CharT>
     using base = std::numpunct<CharT>;
 
 public:
-    using string_type = base::string_type;
+    using string_type = typename base::string_type;
 
 protected:
     string_type do_truename() const override
@@ -262,6 +262,9 @@ struct large_unformattable_type
 struct custom_type
 {
     int val = 0;
+
+    custom_type(int v)
+        : val(v) {}
 };
 
 struct large_custom_type
diff --git a/test/test_utility.cpp b/test/test_utility.cpp
index 9b02c2c..4bb6d80 100644
--- a/test/test_utility.cpp
+++ b/test/test_utility.cpp
@@ -283,11 +283,9 @@ TEST(basic_oiterstream, char)
     using namespace papilio;
 
     std::string buf;
-    oiterstream os(std::back_inserter(buf));
-
-    static_assert(std::is_same_v<
-                  decltype(os)::iterator,
-                  std::back_insert_iterator<std::string>>);
+    oiterstream<std::back_insert_iterator<std::string>> os(
+        std::back_inserter(buf)
+    );
 
     os << "hello";
     os << ' ';
@@ -302,11 +300,9 @@ TEST(basic_oiterstream, wchar_t)
     using namespace papilio;
 
     std::wstring buf;
-    woiterstream os(std::back_inserter(buf));
-
-    static_assert(std::is_same_v<
-                  decltype(os)::iterator,
-                  std::back_insert_iterator<std::wstring>>);
+    woiterstream<std::back_insert_iterator<std::wstring>> os(
+        std::back_inserter(buf)
+    );
 
     os << L"hello";
     os << L' ';