Apply clang-tidy

include/fmt/args.h

@@ -212,7 +212,7 @@ FMT_EXPORT template <typename Context> class dynamic_format_arg_store {
   }
 
   /// Returns the number of elements in the store.
-  size_t size() const noexcept { return data_.size(); }
+  auto size() const noexcept -> size_t { return data_.size(); }
 };
 
 FMT_END_NAMESPACE

include/fmt/base.h

@@ -458,8 +458,10 @@ enum { use_utf8 = !FMT_WIN32 || is_utf8_enabled };
 static_assert(!FMT_UNICODE || use_utf8,
               "Unicode support requires compiling with /utf-8");
 
-template <typename T> constexpr const char* narrow(const T*) { return nullptr; }
-constexpr FMT_ALWAYS_INLINE const char* narrow(const char* s) { return s; }
+template <typename T> constexpr auto narrow(T*) -> char* { return nullptr; }
+constexpr FMT_ALWAYS_INLINE auto narrow(const char* s) -> const char* {
+  return s;
+}
 
 template <typename Char>
 FMT_CONSTEXPR auto compare(const Char* s1, const Char* s2, size_t n) -> int {
@@ -762,7 +764,7 @@ class basic_specs {
             (static_cast<unsigned>(p) << precision_shift);
   }
 
-  constexpr bool dynamic() const {
+  constexpr auto dynamic() const -> bool {
     return (data_ & (width_mask | precision_mask)) != 0;
   }
 
@@ -2369,8 +2371,8 @@ struct named_arg_store {
   }
 
   named_arg_store(const named_arg_store& rhs) = delete;
-  named_arg_store& operator=(const named_arg_store& rhs) = delete;
-  named_arg_store& operator=(named_arg_store&& rhs) = delete;
+  auto operator=(const named_arg_store& rhs) -> named_arg_store& = delete;
+  auto operator=(named_arg_store&& rhs) -> named_arg_store& = delete;
   operator const arg_t<Context, NUM_ARGS>*() const { return args + 1; }
 };
 

include/fmt/chrono.h

@@ -1000,16 +1000,16 @@ template <typename T>
 struct has_tm_zone<T, void_t<decltype(T::tm_zone)>> : std::true_type {};
 
 template <typename T, FMT_ENABLE_IF(has_tm_zone<T>::value)>
-bool set_tm_zone(T& time, char* tz) {
+auto set_tm_zone(T& time, char* tz) -> bool {
   time.tm_zone = tz;
   return true;
 }
 template <typename T, FMT_ENABLE_IF(!has_tm_zone<T>::value)>
-bool set_tm_zone(T&, char*) {
+auto set_tm_zone(T&, char*) -> bool {
   return false;
 }
 
-inline char* utc() {
+inline auto utc() -> char* {
   static char tz[] = "UTC";
   return tz;
 }

include/fmt/compile.h

@@ -71,8 +71,8 @@ template <typename... T> struct type_list {};
 
 // Returns a reference to the argument at index N from [first, rest...].
 template <int N, typename T, typename... Args>
-constexpr const auto& get([[maybe_unused]] const T& first,
-                          [[maybe_unused]] const Args&... rest) {
+constexpr auto get([[maybe_unused]] const T& first,
+                   [[maybe_unused]] const Args&... rest) -> const auto& {
   static_assert(N < 1 + sizeof...(Args), "index is out of bounds");
   if constexpr (N == 0)
     return first;

include/fmt/format-inl.h

@@ -1162,7 +1162,7 @@ auto is_left_endpoint_integer_shorter_interval(int exponent) noexcept -> bool {
 }
 
 // Remove trailing zeros from n and return the number of zeros removed (float).
-FMT_INLINE int remove_trailing_zeros(uint32_t& n, int s = 0) noexcept {
+FMT_INLINE auto remove_trailing_zeros(uint32_t& n, int s = 0) noexcept -> int {
   FMT_ASSERT(n != 0, "");
   // Modular inverse of 5 (mod 2^32): (mod_inv_5 * 5) mod 2^32 = 1.
   constexpr uint32_t mod_inv_5 = 0xcccccccd;
@@ -1183,7 +1183,7 @@ FMT_INLINE int remove_trailing_zeros(uint32_t& n, int s = 0) noexcept {
 }
 
 // Removes trailing zeros and returns the number of zeros removed (double).
-FMT_INLINE int remove_trailing_zeros(uint64_t& n) noexcept {
+FMT_INLINE auto remove_trailing_zeros(uint64_t& n) noexcept -> int {
   FMT_ASSERT(n != 0, "");
 
   // Is n is divisible by 10^8?
@@ -1219,7 +1219,7 @@ FMT_INLINE int remove_trailing_zeros(uint64_t& n) noexcept {
 
 // The main algorithm for shorter interval case
 template <typename T>
-FMT_INLINE decimal_fp<T> shorter_interval_case(int exponent) noexcept {
+FMT_INLINE auto shorter_interval_case(int exponent) noexcept -> decimal_fp<T> {
   decimal_fp<T> ret_value;
   // Compute k and beta
   const int minus_k = floor_log10_pow2_minus_log10_4_over_3(exponent);
@@ -1555,7 +1555,7 @@ template <typename F> class glibc_file : public file_base<F> {
 
   void advance_write_buffer(size_t size) { this->file_->_IO_write_ptr += size; }
 
-  bool needs_flush() const {
+  auto needs_flush() const -> bool {
     if ((this->file_->_flags & line_buffered) == 0) return false;
     char* end = this->file_->_IO_write_end;
     auto size = max_of<ptrdiff_t>(this->file_->_IO_write_ptr - end, 0);
@@ -1604,7 +1604,7 @@ template <typename F> class apple_file : public file_base<F> {
     this->file_->_w -= size;
   }
 
-  bool needs_flush() const {
+  auto needs_flush() const -> bool {
     if ((this->file_->_flags & line_buffered) == 0) return false;
     return memchr(this->file_->_p + this->file_->_w, '\n',
                   to_unsigned(-this->file_->_w));

include/fmt/format.h

@@ -736,7 +736,7 @@ using is_double_double = bool_constant<std::numeric_limits<T>::digits == 106>;
 template <typename T> struct allocator : private std::decay<void> {
   using value_type = T;
 
-  T* allocate(size_t n) {
+  auto allocate(size_t n) -> T* {
     FMT_ASSERT(n <= max_value<size_t>() / sizeof(T), "");
     T* p = static_cast<T*>(std::malloc(n * sizeof(T)));
     if (!p) FMT_THROW(std::bad_alloc());
@@ -940,7 +940,7 @@ class string_buffer {
   inline string_buffer() : buf_(str_) {}
 
   inline operator writer() { return buf_; }
-  inline std::string& str() { return str_; }
+  inline auto str() -> std::string& { return str_; }
 };
 
 template <typename T, size_t SIZE, typename Allocator>
@@ -2622,7 +2622,7 @@ FMT_CONSTEXPR auto isfinite(T value) -> bool {
 }
 
 template <typename T, FMT_ENABLE_IF(is_floating_point<T>::value)>
-FMT_INLINE FMT_CONSTEXPR bool signbit(T value) {
+FMT_INLINE FMT_CONSTEXPR auto signbit(T value) -> bool {
   if (is_constant_evaluated()) {
 #ifdef __cpp_if_constexpr
     if constexpr (std::numeric_limits<double>::is_iec559) {
@@ -3698,9 +3698,9 @@ FMT_CONSTEXPR auto get_arg(Context& ctx, ID id) -> basic_format_arg<Context> {
 }
 
 template <typename Context>
-FMT_CONSTEXPR int get_dynamic_spec(
+FMT_CONSTEXPR auto get_dynamic_spec(
     arg_id_kind kind, const arg_ref<typename Context::char_type>& ref,
-    Context& ctx) {
+    Context& ctx) -> int {
   FMT_ASSERT(kind != arg_id_kind::none, "");
   auto arg =
       kind == arg_id_kind::index ? ctx.arg(ref.index) : ctx.arg(ref.name);

include/fmt/std.h

@@ -129,9 +129,8 @@ struct is_variant_like_<std::variant<Types...>> : std::true_type {};
 
 template <typename Variant, typename Char> class is_variant_formattable {
   template <size_t... Is>
-  static std::conjunction<
-      is_formattable<std::variant_alternative_t<Is, Variant>, Char>...>
-      check(std::index_sequence<Is...>);
+  static auto check(std::index_sequence<Is...>) -> std::conjunction<
+      is_formattable<std::variant_alternative_t<Is, Variant>, Char>...>;
 
  public:
   static constexpr bool value = decltype(check(