diff --git a/format.cc b/format.cc
index 4857b3f4..9faebf47 100644
--- a/format.cc
+++ b/format.cc
@@ -51,6 +51,7 @@
 #endif
 
 using fmt::ULongLong;
+using fmt::internal::Arg;
 
 #if _MSC_VER
 # pragma warning(push)
@@ -118,10 +119,9 @@ void ReportError(FormatFunc func,
   } catch (...) {}
 }
 
-const fmt::internal::ArgInfo DUMMY_ARG = {fmt::internal::ArgInfo::INT, 0};
+const Arg DUMMY_ARG = {Arg::INT, 0};
 
-fmt::ULongLong GetIntValue(const fmt::internal::ArgInfo &arg) {
-  typedef fmt::internal::ArgInfo Arg;
+fmt::ULongLong GetIntValue(const Arg &arg) {
   switch (arg.type) {
     case Arg::INT:
       return arg.int_value;
@@ -135,6 +135,25 @@ fmt::ULongLong GetIntValue(const fmt::internal::ArgInfo &arg) {
       return -1;
   }
 }
+
+// Parses an unsigned integer advancing s to the end of the parsed input.
+// This function assumes that the first character of s is a digit.
+template <typename Char>
+int ParseNonnegativeInt(const Char *&s, const char *&error) FMT_NOEXCEPT(true) {
+  assert('0' <= *s && *s <= '9');
+  unsigned value = 0;
+  do {
+    unsigned new_value = value * 10 + (*s++ - '0');
+    // Check if value wrapped around.
+    value = new_value >= value ? new_value : UINT_MAX;
+  } while ('0' <= *s && *s <= '9');
+  if (value > INT_MAX) {
+    if (!error)
+      error = "number is too big in format";
+    return 0;
+  }
+  return value;
+}
 }  // namespace
 
 int fmt::internal::SignBitNoInline(double value) { return SignBit(value); }
@@ -349,26 +368,6 @@ void fmt::internal::FormatErrorReporter<Char>::operator()(
   throw fmt::FormatError("unmatched '{' in format");
 }
 
-// Parses an unsigned integer advancing s to the end of the parsed input.
-// This function assumes that the first character of s is a digit.
-template <typename Char>
-int fmt::internal::ParseNonnegativeInt(
-    const Char *&s, const char *&error) FMT_NOEXCEPT(true) {
-  assert('0' <= *s && *s <= '9');
-  unsigned value = 0;
-  do {
-    unsigned new_value = value * 10 + (*s++ - '0');
-    // Check if value wrapped around.
-    value = new_value >= value ? new_value : UINT_MAX;
-  } while ('0' <= *s && *s <= '9');
-  if (value > INT_MAX) {
-    if (!error)
-      error = "number is too big in format";
-    return 0;
-  }
-  return value;
-}
-
 // Fills the padding around the content and returns the pointer to the
 // content area.
 template <typename Char>
@@ -553,7 +552,7 @@ void fmt::BasicWriter<Char>::write_str(
 }
 
 template <typename Char>
-inline const typename fmt::BasicWriter<Char>::Arg
+inline const Arg
     &fmt::BasicWriter<Char>::FormatParser::ParseArgIndex(const Char *&s) {
   unsigned arg_index = 0;
   if (*s < '0' || *s > '9') {
@@ -571,7 +570,7 @@ inline const typename fmt::BasicWriter<Char>::Arg
     }
     next_arg_index_ = -1;
     const char *error = 0;
-    arg_index = internal::ParseNonnegativeInt(s, error);
+    arg_index = ParseNonnegativeInt(s, error);
     if (error)
       report_error_(s, error); // TODO
   }
@@ -630,7 +629,7 @@ unsigned fmt::internal::PrintfParser<Char>::ParseHeader(
   if (c >= '0' && c <= '9') {
     // Parse an argument index (if followed by '$') or a width possibly
     // preceded with '0' flag(s).
-    unsigned value = internal::ParseNonnegativeInt(s, error);
+    unsigned value = ParseNonnegativeInt(s, error);
     if (*s == '$') {  // value is an argument index
       ++s;
       arg_index = value;
@@ -648,7 +647,7 @@ unsigned fmt::internal::PrintfParser<Char>::ParseHeader(
   ParseFlags(spec, s);
   // Parse width.
   if (*s >= '0' && *s <= '9') {
-    spec.width_ = internal::ParseNonnegativeInt(s, error);
+    spec.width_ = ParseNonnegativeInt(s, error);
   } else if (*s == '*') {
     ++s;
     const Arg &arg = HandleArgIndex(UINT_MAX, error);
@@ -689,8 +688,7 @@ unsigned fmt::internal::PrintfParser<Char>::ParseHeader(
 
 // TODO: move to a base class that doesn't depend on template argument
 template <typename Char>
-const fmt::internal::ArgInfo
-  &fmt::internal::PrintfParser<Char>::HandleArgIndex(
+const Arg &fmt::internal::PrintfParser<Char>::HandleArgIndex(
     unsigned arg_index, const char *&error) {
   if (arg_index != UINT_MAX) {
     if (next_arg_index_ <= 0) {
@@ -751,7 +749,7 @@ void fmt::internal::PrintfParser<Char>::Format(
     if (*s == '.') {
       ++s;
       if ('0' <= *s && *s <= '9') {
-        spec.precision_ = internal::ParseNonnegativeInt(s, error);
+        spec.precision_ = ParseNonnegativeInt(s, error);
       } else if (*s == '*') {
         ++s;
         const Arg &arg = HandleArgIndex(UINT_MAX, error);
@@ -957,7 +955,7 @@ void fmt::BasicWriter<Char>::FormatParser::Format(
         }
         // Zero may be parsed again as a part of the width, but it is simpler
         // and more efficient than checking if the next char is a digit.
-        spec.width_ = internal::ParseNonnegativeInt(s, error);
+        spec.width_ = ParseNonnegativeInt(s, error);
         if (error)
           report_error_(s, error);
       }
@@ -967,7 +965,7 @@ void fmt::BasicWriter<Char>::FormatParser::Format(
         ++s;
         spec.precision_ = 0;
         if ('0' <= *s && *s <= '9') {
-          spec.precision_ = internal::ParseNonnegativeInt(s, error);
+          spec.precision_ = ParseNonnegativeInt(s, error);
           if (error)
             report_error_(s, error);
         } else if (*s == '{') {
diff --git a/format.h b/format.h
index e101c5fa..f7120cff 100644
--- a/format.h
+++ b/format.h
@@ -562,12 +562,6 @@ struct FormatErrorReporter {
   void operator()(const Char *s, fmt::StringRef message) const;
 };
 
-// Parses a nonnegative integer advancing s to the end of the parsed input.
-// This function assumes that the first character of s is a digit.
-template <typename Char>
-int ParseNonnegativeInt(
-  const Char *&s, const char *&error) FMT_NOEXCEPT(true);
-
 // Computes max(Arg, 1) at compile time. It is used to avoid errors about
 // allocating an array of 0 size.
 template <unsigned Arg>
@@ -580,9 +574,8 @@ struct NonZero<0> {
   enum { VALUE = 1 };
 };
 
-// Information about a format argument. It is a POD type to allow
-// storage in internal::Array.
-struct ArgInfo {
+// A formatting argument. It is a POD type to allow storage in internal::Array.
+struct Arg {
   enum Type {
     // Integer types should go first,
     INT, UINT, LONG_LONG, ULONG_LONG, LAST_INTEGER_TYPE = ULONG_LONG,
@@ -614,9 +607,9 @@ struct ArgInfo {
   };
 };
 
-// Makes an ArgInfo object from any type.
+// Makes an Arg object from any type.
 template <typename Char>
-class MakeArg : public internal::ArgInfo {
+class MakeArg : public Arg {
  private:
   // This method is private to disallow formatting of arbitrary pointers.
   // If you want to output a pointer cast it to const void*. Do not implement!
@@ -629,8 +622,6 @@ class MakeArg : public internal::ArgInfo {
   MakeArg(T *value);
 
  public:
-  using internal::ArgInfo::type;
-
   MakeArg() {}
   // TODO: unsigned char & signed char
   MakeArg(short value) { type = INT; int_value = value; }
@@ -718,12 +709,12 @@ class RuntimeError : public std::runtime_error {
  */
 class ArgList {
  private:
-  const internal::ArgInfo *args_;
+  const internal::Arg *args_;
   std::size_t size_;
 
  public:
   ArgList() : size_(0) {}
-  ArgList(const internal::ArgInfo *args, std::size_t size)
+  ArgList(const internal::Arg *args, std::size_t size)
   : args_(args), size_(size) {}
 
   /**
@@ -734,7 +725,7 @@ class ArgList {
   /**
     Returns the argument at specified index.
    */
-  const internal::ArgInfo &operator[](std::size_t index) const {
+  const internal::Arg &operator[](std::size_t index) const {
     return args_[index];
   }
 };
@@ -747,15 +738,13 @@ class PrintfParser {
   ArgList args_;
   int next_arg_index_;
   
-  typedef ArgInfo Arg;
-
   void ParseFlags(FormatSpec &spec, const Char *&s);
 
   // Parses argument index, flags and width and returns the parsed
   // argument index.
   unsigned ParseHeader(const Char *&s, FormatSpec &spec, const char *&error);
 
-  const ArgInfo &HandleArgIndex(unsigned arg_index, const char *&error);
+  const internal::Arg &HandleArgIndex(unsigned arg_index, const char *&error);
 
  public:
   void Format(BasicWriter<Char> &writer,
@@ -1012,7 +1001,8 @@ inline StrFormatSpec<wchar_t> pad(
 # define FMT_VARIADIC_VOID(func, arg_type) \
   template<typename... Args> \
   void func(arg_type arg1, const Args & ... args) { \
-    const internal::ArgInfo arg_array[fmt::internal::NonZero<sizeof...(Args)>::VALUE] = { \
+    using fmt::internal::Arg; \
+    const Arg arg_array[fmt::internal::NonZero<sizeof...(Args)>::VALUE] = { \
       fmt::internal::MakeArg<Char>(args)... \
     }; \
     func(arg1, ArgList(arg_array, sizeof...(Args))); \
@@ -1022,7 +1012,8 @@ inline StrFormatSpec<wchar_t> pad(
 # define FMT_VARIADIC_CTOR(ctor, func, arg0_type, arg1_type) \
   template<typename... Args> \
   ctor(arg0_type arg0, arg1_type arg1, const Args & ... args) { \
-    const internal::ArgInfo arg_array[fmt::internal::NonZero<sizeof...(Args)>::VALUE] = { \
+    using fmt::internal::Arg; \
+    const Arg arg_array[fmt::internal::NonZero<sizeof...(Args)>::VALUE] = { \
       fmt::internal::MakeArg<Char>(args)... \
     }; \
     func(arg0, arg1, ArgList(arg_array, sizeof...(Args))); \
@@ -1036,7 +1027,7 @@ inline StrFormatSpec<wchar_t> pad(
 # define FMT_WRAP1(func, arg_type, n) \
   template <FMT_GEN(n, FMT_MAKE_TEMPLATE_ARG)> \
   inline void func(arg_type arg1, FMT_GEN(n, FMT_MAKE_ARG)) { \
-    const fmt::internal::ArgInfo args[] = {FMT_GEN(n, FMT_MAKE_REF)}; \
+    const fmt::internal::Arg args[] = {FMT_GEN(n, FMT_MAKE_REF)}; \
     func(arg1, fmt::ArgList(args, sizeof(args) / sizeof(*args))); \
   }
 
@@ -1051,7 +1042,7 @@ inline StrFormatSpec<wchar_t> pad(
 # define FMT_CTOR(ctor, func, arg0_type, arg1_type, n) \
   template <FMT_GEN(n, FMT_MAKE_TEMPLATE_ARG)> \
   ctor(arg0_type arg0, arg1_type arg1, FMT_GEN(n, FMT_MAKE_ARG)) { \
-    const fmt::internal::ArgInfo args[] = {FMT_GEN(n, FMT_MAKE_REF)}; \
+    const fmt::internal::Arg args[] = {FMT_GEN(n, FMT_MAKE_REF)}; \
     func(arg0, arg1, fmt::ArgList(args, sizeof(args) / sizeof(*args))); \
   }
 
@@ -1165,8 +1156,6 @@ class BasicWriter {
 
   typedef typename internal::CharTraits<Char>::CharPtr CharPtr;
 
-  typedef internal::ArgInfo Arg;
-
 #if _SECURE_SCL
   static Char *GetBase(CharPtr p) { return p.base(); }
 #else
@@ -1228,9 +1217,9 @@ class BasicWriter {
     fmt::internal::FormatErrorReporter<Char> report_error_;
 
     // Parses argument index and returns an argument with this index.
-    const Arg &ParseArgIndex(const Char *&s);
+    const internal::Arg &ParseArgIndex(const Char *&s);
 
-    void CheckSign(const Char *&s, const Arg &arg);
+    void CheckSign(const Char *&s, const internal::Arg &arg);
 
    public:
     void Format(BasicWriter<Char> &writer,
@@ -1834,8 +1823,8 @@ inline void FormatDec(char *&buffer, T value) {
   template<typename... Args> \
   ReturnType func(FMT_FOR_EACH(FMT_ADD_ARG_NAME, __VA_ARGS__), \
       const Args & ... args) { \
-    enum {N = fmt::internal::NonZero<sizeof...(Args)>::VALUE}; \
-    const fmt::internal::ArgInfo array[N] = { \
+    using fmt::internal::Arg; \
+    const Arg array[fmt::internal::NonZero<sizeof...(Args)>::VALUE] = { \
       fmt::internal::MakeArg<Char>(args)... \
     }; \
     call(FMT_FOR_EACH(FMT_GET_ARG_NAME, __VA_ARGS__), \
@@ -1848,7 +1837,7 @@ inline void FormatDec(char *&buffer, T value) {
   template <FMT_GEN(n, FMT_MAKE_TEMPLATE_ARG)> \
   inline ReturnType func(FMT_FOR_EACH(FMT_ADD_ARG_NAME, __VA_ARGS__), \
       FMT_GEN(n, FMT_MAKE_ARG)) { \
-    const fmt::internal::ArgInfo args[] = {FMT_GEN(n, FMT_MAKE_REF_##Char)}; \
+    const fmt::internal::Arg args[] = {FMT_GEN(n, FMT_MAKE_REF_##Char)}; \
     call(FMT_FOR_EACH(FMT_GET_ARG_NAME, __VA_ARGS__), \
       fmt::ArgList(args, sizeof(args) / sizeof(*args))); \
   }