format.hpp - OpenGrok cross reference for /dports/www/davix/davix-0.7.6/src/libs/alibxx/str/format.hpp

/*
 Forked form cppformat (original author Victor Zverovich)
 */

#ifndef FMT_FORMAT_HPP_
#define FMT_FORMAT_HPP_

#include <stdint.h>

#include <cassert>
#include <cmath>
#include <cstddef>  // for std::ptrdiff_t
#include <cstdio>
#include <algorithm>
#include <limits>
#include <stdexcept>
#include <string>
#include <sstream>

// define A_LIB_NAMESPACE to empty if not define
// trigger compilation error if not defined properly
#ifndef A_LIB_NAMESPACE
#error "A_LIB_NAMESPACE need to be defined"
#endif

namespace A_LIB_NAMESPACE {


#if _SECURE_SCL
# include <iterator>
#endif

#ifdef __GNUC__
# define FMT_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
# define FMT_GCC_EXTENSION __extension__
// Disable warning about "long long" which is sometimes reported even
// when using __extension__.
# if FMT_GCC_VERSION >= 406
#  pragma GCC diagnostic push
#  pragma GCC diagnostic ignored "-Wlong-long"
# endif
#else
# define FMT_GCC_EXTENSION
#endif

#ifdef __GNUC_LIBSTD__
# define FMT_GNUC_LIBSTD_VERSION (__GNUC_LIBSTD__ * 100 + __GNUC_LIBSTD_MINOR__)
#endif

#ifdef __has_feature
# define FMT_HAS_FEATURE(x) __has_feature(x)
#else
# define FMT_HAS_FEATURE(x) 0
#endif

#ifdef __has_builtin
# define FMT_HAS_BUILTIN(x) __has_builtin(x)
#else
# define FMT_HAS_BUILTIN(x) 0
#endif

#ifndef FMT_USE_VARIADIC_TEMPLATES
// Variadic templates are available in GCC since version 4.4
// (http://gcc.gnu.org/projects/cxx0x.html) and in Visual C++
// since version 2013.
# define FMT_USE_VARIADIC_TEMPLATES \
   (FMT_HAS_FEATURE(cxx_variadic_templates) || \
       (FMT_GCC_VERSION >= 404 && __cplusplus >= 201103) || _MSC_VER >= 1800)
#endif

#ifndef FMT_USE_RVALUE_REFERENCES
// Don't use rvalue references when compiling with clang and an old libstdc++
// as the latter doesn't provide std::move.
# if defined(FMT_GNUC_LIBSTD_VERSION) && FMT_GNUC_LIBSTD_VERSION <= 402
#  define FMT_USE_RVALUE_REFERENCES 0
# else
#  define FMT_USE_RVALUE_REFERENCES \
    (FMT_HAS_FEATURE(cxx_rvalue_references) || \
        (FMT_GCC_VERSION >= 403 && __cplusplus >= 201103) || _MSC_VER >= 1600)
# endif
#endif

#if FMT_USE_RVALUE_REFERENCES
# include <utility>  // for std::move
#endif

// Define FMT_USE_NOEXCEPT to make C++ Format use noexcept (C++11 feature).
#if FMT_USE_NOEXCEPT || FMT_HAS_FEATURE(cxx_noexcept) || \
  (FMT_GCC_VERSION >= 408 && __cplusplus >= 201103)
# define FMT_NOEXCEPT(expr) noexcept(expr)
#else
# define FMT_NOEXCEPT(expr)
#endif

// A macro to disallow the copy constructor and operator= functions
// This should be used in the private: declarations for a class
#define FMT_DISALLOW_COPY_AND_ASSIGN(TypeName) \
  TypeName(const TypeName&); \
  void operator=(const TypeName&)

namespace fmt {

// Fix the warning about long long on older versions of GCC
// that don't support the diagnostic pragma.
FMT_GCC_EXTENSION typedef long long LongLong;
FMT_GCC_EXTENSION typedef unsigned long long ULongLong;

#if FMT_USE_RVALUE_REFERENCES
using std::move;
#endif

template <typename Char>
class BasicWriter;

typedef BasicWriter<char> Writer;
typedef BasicWriter<wchar_t> WWriter;

template <typename Char>
class BasicFormatter;

template <typename Char, typename T>
void format(BasicFormatter<Char> &f, const Char *&format_str, const T &value);

/**
  \rst
  A string reference. It can be constructed from a C string or
  ``std::string``.

  You can use one of the following typedefs for common character types:

  +------------+-------------------------+
  | Type       | Definition              |
  +============+=========================+
  | StringRef  | BasicStringRef<char>    |
  +------------+-------------------------+
  | WStringRef | BasicStringRef<wchar_t> |
  +------------+-------------------------+

  This class is most useful as a parameter type to allow passing
  different types of strings to a function, for example::

    template <typename... Args>
    std::string format(StringRef format, const Args & ... args);

    format("{}", 42);
    format(std::string("{}"), 42);
  \endrst
 */
template <typename Char>
class BasicStringRef {
 private:
  const Char *data_;
  std::size_t size_;

 public:
  /**
    Constructs a string reference object from a C string and a size.
   */
  BasicStringRef(const Char *s, std::size_t size) : data_(s), size_(size) {}

  /**
    Constructs a string reference object from a C string computing
    the size with ``std::char_traits<Char>::length``.
   */
  BasicStringRef(const Char *s)
    : data_(s), size_(std::char_traits<Char>::length(s)) {}

  /**
    Constructs a string reference from an `std::string` object.
   */
  BasicStringRef(const std::basic_string<Char> &s)
  : data_(s.c_str()), size_(s.size()) {}

  /**
    Converts a string reference to an `std::string` object.
   */
  operator std::basic_string<Char>() const {
    return std::basic_string<Char>(data_, size());
  }

  /**
    Returns the pointer to a C string.
   */
  const Char *c_str() const { return data_; }

  /**
    Returns the string size.
   */
  std::size_t size() const { return size_; }

  friend bool operator==(BasicStringRef lhs, BasicStringRef rhs) {
    return lhs.data_ == rhs.data_;
  }
  friend bool operator!=(BasicStringRef lhs, BasicStringRef rhs) {
    return lhs.data_ != rhs.data_;
  }
};

typedef BasicStringRef<char> StringRef;
typedef BasicStringRef<wchar_t> WStringRef;

/**
  A formatting error such as invalid format string.
*/
class FormatError : public std::runtime_error {
public:
  explicit FormatError(StringRef message)
  : std::runtime_error(message.c_str()) {}
};

namespace internal {

// The number of characters to store in the MemoryBuffer object itself
// to avoid dynamic memory allocation.
enum { INLINE_BUFFER_SIZE = 500 };

#if _SECURE_SCL
// Use checked iterator to avoid warnings on MSVC.
template <typename T>
inline stdext::checked_array_iterator<T*> make_ptr(T *ptr, std::size_t size) {
  return stdext::checked_array_iterator<T*>(ptr, size);
}
#else
template <typename T>
inline T *make_ptr(T *ptr, std::size_t) { return ptr; }
#endif

// A buffer for POD types. It supports a subset of std::vector's operations.
template <typename T>
class Buffer {
 private:
  FMT_DISALLOW_COPY_AND_ASSIGN(Buffer);

 protected:
  T *ptr_;
  std::size_t size_;
  std::size_t capacity_;

  Buffer(T *ptr = 0, std::size_t capacity = 0)
    : ptr_(ptr), size_(0), capacity_(capacity) {}

  virtual void grow(std::size_t size) = 0;

 public:
  virtual ~Buffer() {}

  // Returns the size of this buffer.
  std::size_t size() const { return size_; }

  // Returns the capacity of this buffer.
  std::size_t capacity() const { return capacity_; }

  // Resizes the buffer. If T is a POD type new elements are not initialized.
  void resize(std::size_t new_size) {
    if (new_size > capacity_)
      grow(new_size);
    size_ = new_size;
  }

  // Reserves space to store at least capacity elements.
  void reserve(std::size_t capacity) {
    if (capacity > capacity_)
      grow(capacity);
  }

  void clear() FMT_NOEXCEPT(true) { size_ = 0; }

  void push_back(const T &value) {
    if (size_ == capacity_)
      grow(size_ + 1);
    ptr_[size_++] = value;
  }

  // Appends data to the end of the buffer.
  void append(const T *begin, const T *end);

  T &operator[](std::size_t index) { return ptr_[index]; }
  const T &operator[](std::size_t index) const { return ptr_[index]; }
};

template <typename T>
void Buffer<T>::append(const T *begin, const T *end) {
  std::ptrdiff_t num_elements = end - begin;
  if (size_ + num_elements > capacity_)
    grow(size_ + num_elements);
  std::copy(begin, end, make_ptr(ptr_, capacity_) + size_);
  size_ += num_elements;
}

// A memory buffer for POD types with the first SIZE elements stored in
// the object itself.
template <typename T, std::size_t SIZE, typename Allocator = std::allocator<T> >
class MemoryBuffer : private Allocator, public Buffer<T> {
 private:
  T data_[SIZE];

  // Free memory allocated by the buffer.
  void free() {
    if (this->ptr_ != data_) this->deallocate(this->ptr_, this->capacity_);
  }

 protected:
  void grow(std::size_t size);

 public:
  explicit MemoryBuffer(const Allocator &alloc = Allocator())
      : Allocator(alloc), Buffer<T>(data_, SIZE) {}
  ~MemoryBuffer() { free(); }

#if FMT_USE_RVALUE_REFERENCES
 private:
  // Move data from other to this buffer.
  void move(MemoryBuffer &other) {
    Allocator &this_alloc = *this, &other_alloc = other;
    this_alloc = std::move(other_alloc);
    this->size_ = other.size_;
    this->capacity_ = other.capacity_;
    if (other.ptr_ == other.data_) {
      this->ptr_ = data_;
      std::copy(other.data_,
                other.data_ + this->size_, make_ptr(data_, this->capacity_));
    } else {
      this->ptr_ = other.ptr_;
      // Set pointer to the inline array so that delete is not called
      // when freeing.
      other.ptr_ = other.data_;
    }
  }

 public:
  MemoryBuffer(MemoryBuffer &&other) {
    move(other);
  }

  MemoryBuffer &operator=(MemoryBuffer &&other) {
    assert(this != &other);
    free();
    move(other);
    return *this;
  }
#endif

  // Returns a copy of the allocator associated with this buffer.
  Allocator get_allocator() const { return *this; }
};

template <typename T, std::size_t SIZE, typename Allocator>
void MemoryBuffer<T, SIZE, Allocator>::grow(std::size_t size) {
  std::size_t new_capacity =
      (std::max)(size, this->capacity_ + this->capacity_ / 2);
  T *new_ptr = this->allocate(new_capacity);
  // The following code doesn't throw, so the raw pointer above doesn't leak.
  std::copy(this->ptr_,
            this->ptr_ + this->size_, make_ptr(new_ptr, new_capacity));
  std::size_t old_capacity = this->capacity_;
  T *old_ptr = this->ptr_;
  this->capacity_ = new_capacity;
  this->ptr_ = new_ptr;
  // deallocate may throw (at least in principle), but it doesn't matter since
  // the buffer already uses the new storage and will deallocate it in case
  // of exception.
  if (old_ptr != data_)
    this->deallocate(old_ptr, old_capacity);
}

#ifndef _MSC_VER
// Portable version of signbit.
inline int getsign(double x) {
  // When compiled in C++11 mode signbit is no longer a macro but a function
  // defined in namespace std and the macro is undefined.
# ifdef signbit
  return signbit(x);
# else
  return std::signbit(x);
# endif
}

// Portable version of isinf.
# ifdef isinf
inline int isinfinity(double x) { return isinf(x); }
inline int isinfinity(long double x) { return isinf(x); }
# else
inline int isinfinity(double x) { return std::isinf(x); }
inline int isinfinity(long double x) { return std::isinf(x); }
# endif
#else
inline int getsign(double value) {
  if (value < 0) return 1;
  if (value == value) return 0;
  int dec = 0, sign = 0;
  char buffer[2];  // The buffer size must be >= 2 or _ecvt_s will fail.
  _ecvt_s(buffer, sizeof(buffer), value, 0, &dec, &sign);
  return sign;
}
inline int isinfinity(double x) { return !_finite(x); }
#endif

template <typename T>
struct IsLongDouble { enum {VALUE = 0}; };

template <>
struct IsLongDouble<long double> { enum {VALUE = 1}; };

template <typename Char>
class BasicCharTraits {
 public:
#if _SECURE_SCL
  typedef stdext::checked_array_iterator<Char*> CharPtr;
#else
  typedef Char *CharPtr;
#endif
};

template <typename Char>
class CharTraits;

template <>
class CharTraits<char> : public BasicCharTraits<char> {
 private:
  // Conversion from wchar_t to char is not allowed.
  static char convert(wchar_t);

public:
  typedef const wchar_t *UnsupportedStrType;

  static char convert(char value) { return value; }

  // Formats a floating-point number.
  template <typename T>
  static int format_float(char *buffer, std::size_t size,
      const char *format, unsigned width, int precision, T value);
};

template <>
class CharTraits<wchar_t> : public BasicCharTraits<wchar_t> {
 public:
  typedef const char *UnsupportedStrType;

  static wchar_t convert(char value) { return value; }
  static wchar_t convert(wchar_t value) { return value; }

  template <typename T>
  static int format_float(wchar_t *buffer, std::size_t size,
      const wchar_t *format, unsigned width, int precision, T value);
};

// Checks if a number is negative - used to avoid warnings.
template <bool IsSigned>
struct SignChecker {
  template <typename T>
  static bool is_negative(T value) { return value < 0; }
};

template <>
struct SignChecker<false> {
  template <typename T>
  static bool is_negative(T) { return false; }
};

// Returns true if value is negative, false otherwise.
// Same as (value < 0) but doesn't produce warnings if T is an unsigned type.
template <typename T>
inline bool is_negative(T value) {
  return SignChecker<std::numeric_limits<T>::is_signed>::is_negative(value);
}

// Selects uint32_t if FitsIn32Bits is true, uint64_t otherwise.
template <bool FitsIn32Bits>
struct TypeSelector { typedef uint32_t Type; };

template <>
struct TypeSelector<false> { typedef uint64_t Type; };

template <typename T>
struct IntTraits {
  // Smallest of uint32_t and uint64_t that is large enough to represent
  // all values of T.
  typedef typename
    TypeSelector<std::numeric_limits<T>::digits <= 32>::Type MainType;
};

// MakeUnsigned<T>::Type gives an unsigned type corresponding to integer type T.
template <typename T>
struct MakeUnsigned { typedef T Type; };

#define FMT_SPECIALIZE_MAKE_UNSIGNED(T, U) \
  template <> \
  struct MakeUnsigned<T> { typedef U Type; }

FMT_SPECIALIZE_MAKE_UNSIGNED(char, unsigned char);
FMT_SPECIALIZE_MAKE_UNSIGNED(signed char, unsigned char);
FMT_SPECIALIZE_MAKE_UNSIGNED(short, unsigned short);
FMT_SPECIALIZE_MAKE_UNSIGNED(int, unsigned);
FMT_SPECIALIZE_MAKE_UNSIGNED(long, unsigned long);
FMT_SPECIALIZE_MAKE_UNSIGNED(LongLong, ULongLong);

void report_unknown_type(char code, const char *type);

extern const uint32_t POWERS_OF_10_32[];
extern const uint64_t POWERS_OF_10_64[];

#if FMT_GCC_VERSION >= 400 || FMT_HAS_BUILTIN(__builtin_clzll)
// Returns the number of decimal digits in n. Leading zeros are not counted
// except for n == 0 in which case count_digits returns 1.
inline unsigned count_digits(uint64_t n) {
  // Based on http://graphics.stanford.edu/~seander/bithacks.html#IntegerLog10
  // and the benchmark https://github.com/localvoid/cxx-benchmark-count-digits.
  unsigned t = (64 - __builtin_clzll(n | 1)) * 1233 >> 12;
  return t - (n < POWERS_OF_10_64[t]) + 1;
}
# if FMT_GCC_VERSION >= 400 || FMT_HAS_BUILTIN(__builtin_clz)
// Optional version of count_digits for better performance on 32-bit platforms.
inline unsigned count_digits(uint32_t n) {
  uint32_t t = (32 - __builtin_clz(n | 1)) * 1233 >> 12;
  return t - (n < POWERS_OF_10_32[t]) + 1;
}
# endif
#else
// Fallback version of count_digits used when __builtin_clz is not available.
inline unsigned count_digits(uint64_t n) {
  unsigned count = 1;
  for (;;) {
    // Integer division is slow so do it for a group of four digits instead
    // of for every digit. The idea comes from the talk by Alexandrescu
    // "Three Optimization Tips for C++". See speed-test for a comparison.
    if (n < 10) return count;
    if (n < 100) return count + 1;
    if (n < 1000) return count + 2;
    if (n < 10000) return count + 3;
    n /= 10000u;
    count += 4;
  }
}
#endif

extern const char DIGITS[];

// Formats a decimal unsigned integer value writing into buffer.
template <typename UInt, typename Char>
inline void format_decimal(Char *buffer, UInt value, unsigned num_digits) {
  --num_digits;
  while (value >= 100) {
    // Integer division is slow so do it for a group of two digits instead
    // of for every digit. The idea comes from the talk by Alexandrescu
    // "Three Optimization Tips for C++". See speed-test for a comparison.
    unsigned index = (value % 100) * 2;
    value /= 100;
    buffer[num_digits] = DIGITS[index + 1];
    buffer[num_digits - 1] = DIGITS[index];
    num_digits -= 2;
  }
  if (value < 10) {
    *buffer = static_cast<char>('0' + value);
    return;
  }
  unsigned index = static_cast<unsigned>(value * 2);
  buffer[1] = DIGITS[index + 1];
  buffer[0] = DIGITS[index];
}

#ifdef _WIN32
// A converter from UTF-8 to UTF-16.
// It is only provided for Windows since other systems support UTF-8 natively.
class UTF8ToUTF16 {
 private:
  MemoryBuffer<wchar_t, INLINE_BUFFER_SIZE> buffer_;

 public:
  explicit UTF8ToUTF16(StringRef s);
  operator WStringRef() const { return WStringRef(&buffer_[0], size()); }
  size_t size() const { return buffer_.size() - 1; }
  const wchar_t *c_str() const { return &buffer_[0]; }
  std::wstring str() const { return std::wstring(&buffer_[0], size()); }
};

// A converter from UTF-16 to UTF-8.
// It is only provided for Windows since other systems support UTF-8 natively.
class UTF16ToUTF8 {
 private:
  MemoryBuffer<char, INLINE_BUFFER_SIZE> buffer_;

 public:
  UTF16ToUTF8() {}
  explicit UTF16ToUTF8(WStringRef s);
  operator StringRef() const { return StringRef(&buffer_[0], size()); }
  size_t size() const { return buffer_.size() - 1; }
  const char *c_str() const { return &buffer_[0]; }
  std::string str() const { return std::string(&buffer_[0], size()); }

  // Performs conversion returning a system error code instead of
  // throwing exception on conversion error. This method may still throw
  // in case of memory allocation error.
  int convert(WStringRef s);
};
#endif

void format_system_error(fmt::Writer &out, int error_code,
                         fmt::StringRef message) FMT_NOEXCEPT(true);

#ifdef _WIN32
void format_windows_error(fmt::Writer &out, int error_code,
                          fmt::StringRef message) FMT_NOEXCEPT(true);
#endif

// Computes max(Arg, 1) at compile time. It is used to avoid errors about
// allocating an array of 0 size.
template <unsigned Arg>
struct NonZero {
  enum { VALUE = Arg };
};

template <>
struct NonZero<0> {
  enum { VALUE = 1 };
};

// The value of a formatting argument. It is a POD type to allow storage in
// internal::MemoryBuffer.
struct Value {
  template <typename Char>
  struct StringValue {
    const Char *value;
    std::size_t size;
  };

  typedef void (*FormatFunc)(
      void *formatter, const void *arg, void *format_str_ptr);

  struct CustomValue {
    const void *value;
    FormatFunc format;
  };

  union {
    int int_value;
    unsigned uint_value;
    LongLong long_long_value;
    ULongLong ulong_long_value;
    double double_value;
    long double long_double_value;
    const void *pointer;
    StringValue<char> string;
    StringValue<signed char> sstring;
    StringValue<unsigned char> ustring;
    StringValue<wchar_t> wstring;
    CustomValue custom;
  };
};

struct Arg : Value {
  enum Type {
    NONE,
    // Integer types should go first,
    INT, UINT, LONG_LONG, ULONG_LONG, CHAR, LAST_INTEGER_TYPE = CHAR,
    // followed by floating-point types.
    DOUBLE, LONG_DOUBLE, LAST_NUMERIC_TYPE = LONG_DOUBLE,
    CSTRING, STRING, WSTRING, POINTER, CUSTOM
  };
  Type type;
};

// Makes a Value object from any type.
template <typename Char>
class MakeValue : public Value {
 private:
  // The following two methods are private to disallow formatting of
  // arbitrary pointers. If you want to output a pointer cast it to
  // "void *" or "const void *". In particular, this forbids formatting
  // of "[const] volatile char *" which is printed as bool by iostreams.
  // Do not implement!
  template <typename T>
  MakeValue(const T *value);
  template <typename T>
  MakeValue(T *value);

  void set_string(StringRef str) {
    string.value = str.c_str();
    string.size = str.size();
  }

  void set_string(WStringRef str) {
    CharTraits<Char>::convert(wchar_t());
    wstring.value = str.c_str();
    wstring.size = str.size();
  }

  // Formats an argument of a custom type, such as a user-defined class.
  template <typename T>
  static void format_custom_arg(
      void *formatter, const void *arg, void *format_str_ptr) {
    format(*static_cast<BasicFormatter<Char>*>(formatter),
           *static_cast<const Char**>(format_str_ptr),
           *static_cast<const T*>(arg));
  }

public:
  MakeValue() {}

#define FMT_MAKE_VALUE(Type, field, TYPE) \
  MakeValue(Type value) { field = value; } \
  static uint64_t type(Type) { return Arg::TYPE; }

  FMT_MAKE_VALUE(bool, int_value, INT)
  FMT_MAKE_VALUE(short, int_value, INT)
  FMT_MAKE_VALUE(unsigned short, uint_value, UINT)
  FMT_MAKE_VALUE(int, int_value, INT)
  FMT_MAKE_VALUE(unsigned, uint_value, UINT)

  MakeValue(long value) {
    // To minimize the number of types we need to deal with, long is
    // translated either to int or to long long depending on its size.
    if (sizeof(long) == sizeof(int))
      int_value = static_cast<int>(value);
    else
      long_long_value = value;
  }
  static uint64_t type(long) {
    return sizeof(long) == sizeof(int) ? Arg::INT : Arg::LONG_LONG;
  }

  MakeValue(unsigned long value) {
    if (sizeof(unsigned long) == sizeof(unsigned))
      uint_value = static_cast<unsigned>(value);
    else
      ulong_long_value = value;
  }
  static uint64_t type(unsigned long) {
    return sizeof(unsigned long) == sizeof(unsigned) ?
          Arg::UINT : Arg::ULONG_LONG;
  }

  FMT_MAKE_VALUE(LongLong, long_long_value, LONG_LONG)
  FMT_MAKE_VALUE(ULongLong, ulong_long_value, ULONG_LONG)
  FMT_MAKE_VALUE(float, double_value, DOUBLE)
  FMT_MAKE_VALUE(double, double_value, DOUBLE)
  FMT_MAKE_VALUE(long double, long_double_value, LONG_DOUBLE)
  FMT_MAKE_VALUE(signed char, int_value, CHAR)
  FMT_MAKE_VALUE(unsigned char, int_value, CHAR)
  FMT_MAKE_VALUE(char, int_value, CHAR)

  MakeValue(wchar_t value) {
    int_value = internal::CharTraits<Char>::convert(value);
  }
  static uint64_t type(wchar_t) { return Arg::CHAR; }

#define FMT_MAKE_STR_VALUE(Type, TYPE) \
  MakeValue(Type value) { set_string(value); } \
  static uint64_t type(Type) { return Arg::TYPE; }

  FMT_MAKE_VALUE(char *, string.value, CSTRING)
  FMT_MAKE_VALUE(const char *, string.value, CSTRING)
  FMT_MAKE_VALUE(const signed char *, sstring.value, CSTRING)
  FMT_MAKE_VALUE(const unsigned char *, ustring.value, CSTRING)
  FMT_MAKE_STR_VALUE(const std::string &, STRING)
  FMT_MAKE_STR_VALUE(StringRef, STRING)

  FMT_MAKE_STR_VALUE(wchar_t *, WSTRING)
  FMT_MAKE_STR_VALUE(const wchar_t *, WSTRING)
  FMT_MAKE_STR_VALUE(const std::wstring &, WSTRING)
  FMT_MAKE_STR_VALUE(WStringRef, WSTRING)

  FMT_MAKE_VALUE(void *, pointer, POINTER)
  FMT_MAKE_VALUE(const void *, pointer, POINTER)

  template <typename T>
  MakeValue(const T &value) {
    custom.value = &value;
    custom.format = &format_custom_arg<T>;
  }
  template <typename T>
  static uint64_t type(const T &) { return Arg::CUSTOM; }
};

#define FMT_DISPATCH(call) static_cast<Impl*>(this)->call

// An argument visitor.
// To use ArgVisitor define a subclass that implements some or all of the
// visit methods with the same signatures as the methods in ArgVisitor,
// for example, visit_int(int).
// Specify the subclass name as the Impl template parameter. Then calling
// ArgVisitor::visit for some argument will dispatch to a visit method
// specific to the argument type. For example, if the argument type is
// double then visit_double(double) method of a subclass will be called.
// If the subclass doesn't contain a method with this signature, then
// a corresponding method of ArgVisitor will be called.
//
// Example:
//  class MyArgVisitor : public ArgVisitor<MyArgVisitor, void> {
//   public:
//    void visit_int(int value) { print("{}", value); }
//    void visit_double(double value) { print("{}", value ); }
//  };
//
// ArgVisitor uses the curiously recurring template pattern:
// http://en.wikipedia.org/wiki/Curiously_recurring_template_pattern
template <typename Impl, typename Result>
class ArgVisitor {
 public:
  Result visit_unhandled_arg() { return Result(); }

  Result visit_int(int value) {
    return FMT_DISPATCH(visit_any_int(value));
  }
  Result visit_long_long(LongLong value) {
    return FMT_DISPATCH(visit_any_int(value));
  }
  Result visit_uint(unsigned value) {
    return FMT_DISPATCH(visit_any_int(value));
  }
  Result visit_ulong_long(ULongLong value) {
    return FMT_DISPATCH(visit_any_int(value));
  }
  Result visit_char(int value) {
    return FMT_DISPATCH(visit_any_int(value));
  }
  template <typename T>
  Result visit_any_int(T) {
    return FMT_DISPATCH(visit_unhandled_arg());
  }

  Result visit_double(double value) {
    return FMT_DISPATCH(visit_any_double(value));
  }
  Result visit_long_double(long double value) {
    return FMT_DISPATCH(visit_any_double(value));
  }
  template <typename T>
  Result visit_any_double(T) {
    return FMT_DISPATCH(visit_unhandled_arg());
  }

  Result visit_string(Arg::StringValue<char>) {
    return FMT_DISPATCH(visit_unhandled_arg());
  }
  Result visit_wstring(Arg::StringValue<wchar_t>) {
    return FMT_DISPATCH(visit_unhandled_arg());
  }
  Result visit_pointer(const void *) {
    return FMT_DISPATCH(visit_unhandled_arg());
  }
  Result visit_custom(Arg::CustomValue) {
    return FMT_DISPATCH(visit_unhandled_arg());
  }

  Result visit(const Arg &arg) {
    switch (arg.type) {
    default:
      assert(false);
      // Fall through.
    case Arg::INT:
      return FMT_DISPATCH(visit_int(arg.int_value));
    case Arg::UINT:
      return FMT_DISPATCH(visit_uint(arg.uint_value));
    case Arg::LONG_LONG:
      return FMT_DISPATCH(visit_long_long(arg.long_long_value));
    case Arg::ULONG_LONG:
      return FMT_DISPATCH(visit_ulong_long(arg.ulong_long_value));
    case Arg::DOUBLE:
      return FMT_DISPATCH(visit_double(arg.double_value));
    case Arg::LONG_DOUBLE:
      return FMT_DISPATCH(visit_long_double(arg.long_double_value));
    case Arg::CHAR:
      return FMT_DISPATCH(visit_char(arg.int_value));
    case Arg::CSTRING: {
      Value::StringValue<char> str = arg.string;
      str.size = 0;
      return FMT_DISPATCH(visit_string(str));
    }
    case Arg::STRING:
      return FMT_DISPATCH(visit_string(arg.string));
    case Arg::WSTRING:
      return FMT_DISPATCH(visit_wstring(arg.wstring));
    case Arg::POINTER:
      return FMT_DISPATCH(visit_pointer(arg.pointer));
    case Arg::CUSTOM:
      return FMT_DISPATCH(visit_custom(arg.custom));
    }
  }
};

class RuntimeError : public std::runtime_error {
 protected:
  RuntimeError() : std::runtime_error("") {}
};

template <typename Char>
class ArgFormatter;
}  // namespace internal

/**
  An argument list.
 */
class ArgList {
 private:
  uint64_t types_;
  const internal::Value *values_;

 public:
  // Maximum number of arguments that can be passed in ArgList.
  enum { MAX_ARGS = 16 };

  ArgList() : types_(0) {}
  ArgList(ULongLong types, const internal::Value *values)
  : types_(types), values_(values) {}

  /**
    Returns the argument at specified index.
   */
  internal::Arg operator[](unsigned index) const {
    using internal::Arg;
    Arg arg;
    if (index >= MAX_ARGS) {
      arg.type = Arg::NONE;
      return arg;
    }
    unsigned shift = index * 4;
    uint64_t mask = 0xf;
    Arg::Type type =
        static_cast<Arg::Type>((types_ & (mask << shift)) >> shift);
    arg.type = type;
    if (type != Arg::NONE) {
      internal::Value &value = arg;
      value = values_[index];
    }
    return arg;
  }
};

struct FormatSpec;

namespace internal {

class FormatterBase {
 private:
  ArgList args_;
  int next_arg_index_;

  // Returns the argument with specified index.
  Arg do_get_arg(unsigned arg_index, const char *&error);

 protected:
  void set_args(const ArgList &args) {
    args_ = args;
    next_arg_index_ = 0;
  }

  // Returns the next argument.
  Arg next_arg(const char *&error);

  // Checks if manual indexing is used and returns the argument with
  // specified index.
  Arg get_arg(unsigned arg_index, const char *&error);

  template <typename Char>
  void write(BasicWriter<Char> &w, const Char *start, const Char *end) {
    if (start != end)
      w << BasicStringRef<Char>(start, end - start);
  }
};

// A printf formatter.
template <typename Char>
class PrintfFormatter : private FormatterBase {
 private:
  void parse_flags(FormatSpec &spec, const Char *&s);

  // Returns the argument with specified index or, if arg_index is equal
  // to the maximum unsigned value, the next argument.
  Arg get_arg(const Char *s,
      unsigned arg_index = (std::numeric_limits<unsigned>::max)());

  // Parses argument index, flags and width and returns the argument index.
  unsigned parse_header(const Char *&s, FormatSpec &spec);

 public:
  void format(BasicWriter<Char> &writer,
    BasicStringRef<Char> format, const ArgList &args);
};
}  // namespace internal

// A formatter.
template <typename Char>
class BasicFormatter : private internal::FormatterBase {
 private:
  BasicWriter<Char> &writer_;
  const Char *start_;

  // Parses argument index and returns corresponding argument.
  internal::Arg parse_arg_index(const Char *&s);

 public:
  explicit BasicFormatter(BasicWriter<Char> &w) : writer_(w) {}

  BasicWriter<Char> &writer() { return writer_; }

  void format(BasicStringRef<Char> format_str, const ArgList &args);

  const Char *format(const Char *&format_str, const internal::Arg &arg);
};

enum Alignment {
  ALIGN_DEFAULT, ALIGN_LEFT, ALIGN_RIGHT, ALIGN_CENTER, ALIGN_NUMERIC
};

// Flags.
enum {
  SIGN_FLAG = 1, PLUS_FLAG = 2, MINUS_FLAG = 4, HASH_FLAG = 8,
  CHAR_FLAG = 0x10  // Argument has char type - used in error reporting.
};

// An empty format specifier.
struct EmptySpec {};

// A type specifier.
template <char TYPE>
struct TypeSpec : EmptySpec {
  Alignment align() const { return ALIGN_DEFAULT; }
  unsigned width() const { return 0; }
  int precision() const { return -1; }
  bool flag(unsigned) const { return false; }
  char type() const { return TYPE; }
  char fill() const { return ' '; }
};

// A width specifier.
struct WidthSpec {
  unsigned width_;
  // Fill is always wchar_t and cast to char if necessary to avoid having
  // two specialization of WidthSpec and its subclasses.
  wchar_t fill_;

  WidthSpec(unsigned width, wchar_t fill) : width_(width), fill_(fill) {}

  unsigned width() const { return width_; }
  wchar_t fill() const { return fill_; }
};

// An alignment specifier.
struct AlignSpec : WidthSpec {
  Alignment align_;

  AlignSpec(unsigned width, wchar_t fill, Alignment align = ALIGN_DEFAULT)
  : WidthSpec(width, fill), align_(align) {}

  Alignment align() const { return align_; }

  int precision() const { return -1; }
};

// An alignment and type specifier.
template <char TYPE>
struct AlignTypeSpec : AlignSpec {
  AlignTypeSpec(unsigned width, wchar_t fill) : AlignSpec(width, fill) {}

  bool flag(unsigned) const { return false; }
  char type() const { return TYPE; }
};

// A full format specifier.
struct FormatSpec : AlignSpec {
  unsigned flags_;
  int precision_;
  char type_;

  FormatSpec(
    unsigned width = 0, char type = 0, wchar_t fill = ' ')
  : AlignSpec(width, fill), flags_(0), precision_(-1), type_(type) {}

  bool flag(unsigned f) const { return (flags_ & f) != 0; }
  int precision() const { return precision_; }
  char type() const { return type_; }
};

// An integer format specifier.
template <typename T, typename SpecT = TypeSpec<0>, typename Char = char>
class IntFormatSpec : public SpecT {
 private:
  T value_;

 public:
  IntFormatSpec(T value, const SpecT &spec = SpecT())
  : SpecT(spec), value_(value) {}

  T value() const { return value_; }
};

// A string format specifier.
template <typename T>
class StrFormatSpec : public AlignSpec {
 private:
  const T *str_;

 public:
  StrFormatSpec(const T *str, unsigned width, wchar_t fill)
  : AlignSpec(width, fill), str_(str) {}

  const T *str() const { return str_; }
};

/**
  Returns an integer format specifier to format the value in base 2.
 */
IntFormatSpec<int, TypeSpec<'b'> > bin(int value);

/**
  Returns an integer format specifier to format the value in base 8.
 */
IntFormatSpec<int, TypeSpec<'o'> > oct(int value);

/**
  Returns an integer format specifier to format the value in base 16 using
  lower-case letters for the digits above 9.
 */
IntFormatSpec<int, TypeSpec<'x'> > hex(int value);

/**
  Returns an integer formatter format specifier to format in base 16 using
  upper-case letters for the digits above 9.
 */
IntFormatSpec<int, TypeSpec<'X'> > hexu(int value);

/**
  \rst
  Returns an integer format specifier to pad the formatted argument with the
  fill character to the specified width using the default (right) numeric
  alignment.

  **Example**::

    MemoryWriter out;
    out << pad(hex(0xcafe), 8, '0');
    // out.str() == "0000cafe"

  \endrst
 */
template <char TYPE_CODE, typename Char>
IntFormatSpec<int, AlignTypeSpec<TYPE_CODE>, Char> pad(
    int value, unsigned width, Char fill = ' ');

#define FMT_DEFINE_INT_FORMATTERS(TYPE) \
inline IntFormatSpec<TYPE, TypeSpec<'b'> > bin(TYPE value) { \
  return IntFormatSpec<TYPE, TypeSpec<'b'> >(value, TypeSpec<'b'>()); \
} \
 \
inline IntFormatSpec<TYPE, TypeSpec<'o'> > oct(TYPE value) { \
  return IntFormatSpec<TYPE, TypeSpec<'o'> >(value, TypeSpec<'o'>()); \
} \
 \
inline IntFormatSpec<TYPE, TypeSpec<'x'> > hex(TYPE value) { \
  return IntFormatSpec<TYPE, TypeSpec<'x'> >(value, TypeSpec<'x'>()); \
} \
 \
inline IntFormatSpec<TYPE, TypeSpec<'X'> > hexu(TYPE value) { \
  return IntFormatSpec<TYPE, TypeSpec<'X'> >(value, TypeSpec<'X'>()); \
} \
 \
template <char TYPE_CODE> \
inline IntFormatSpec<TYPE, AlignTypeSpec<TYPE_CODE> > pad( \
    IntFormatSpec<TYPE, TypeSpec<TYPE_CODE> > f, unsigned width) { \
  return IntFormatSpec<TYPE, AlignTypeSpec<TYPE_CODE> >( \
      f.value(), AlignTypeSpec<TYPE_CODE>(width, ' ')); \
} \
 \
/* For compatibility with older compilers we provide two overloads for pad, */ \
/* one that takes a fill character and one that doesn't. In the future this */ \
/* can be replaced with one overload making the template argument Char      */ \
/* default to char (C++11). */ \
template <char TYPE_CODE, typename Char> \
inline IntFormatSpec<TYPE, AlignTypeSpec<TYPE_CODE>, Char> pad( \
    IntFormatSpec<TYPE, TypeSpec<TYPE_CODE>, Char> f, \
    unsigned width, Char fill) { \
  return IntFormatSpec<TYPE, AlignTypeSpec<TYPE_CODE>, Char>( \
      f.value(), AlignTypeSpec<TYPE_CODE>(width, fill)); \
} \
 \
inline IntFormatSpec<TYPE, AlignTypeSpec<0> > pad( \
    TYPE value, unsigned width) { \
  return IntFormatSpec<TYPE, AlignTypeSpec<0> >( \
      value, AlignTypeSpec<0>(width, ' ')); \
} \
 \
template <typename Char> \
inline IntFormatSpec<TYPE, AlignTypeSpec<0>, Char> pad( \
   TYPE value, unsigned width, Char fill) { \
 return IntFormatSpec<TYPE, AlignTypeSpec<0>, Char>( \
     value, AlignTypeSpec<0>(width, fill)); \
}

FMT_DEFINE_INT_FORMATTERS(int)
FMT_DEFINE_INT_FORMATTERS(long)
FMT_DEFINE_INT_FORMATTERS(unsigned)
FMT_DEFINE_INT_FORMATTERS(unsigned long)
FMT_DEFINE_INT_FORMATTERS(LongLong)
FMT_DEFINE_INT_FORMATTERS(ULongLong)

/**
  \rst
  Returns a string formatter that pads the formatted argument with the fill
  character to the specified width using the default (left) string alignment.

  **Example**::

    std::string s = str(MemoryWriter() << pad("abc", 8));
    // s == "abc     "

  \endrst
 */
template <typename Char>
inline StrFormatSpec<Char> pad(
    const Char *str, unsigned width, Char fill = ' ') {
  return StrFormatSpec<Char>(str, width, fill);
}

inline StrFormatSpec<wchar_t> pad(
    const wchar_t *str, unsigned width, char fill = ' ') {
  return StrFormatSpec<wchar_t>(str, width, fill);
}

// Generates a comma-separated list with results of applying f to
// numbers 0..n-1.
# define FMT_GEN(n, f) FMT_GEN##n(f)
# define FMT_GEN1(f)  f(0)
# define FMT_GEN2(f)  FMT_GEN1(f),  f(1)
# define FMT_GEN3(f)  FMT_GEN2(f),  f(2)
# define FMT_GEN4(f)  FMT_GEN3(f),  f(3)
# define FMT_GEN5(f)  FMT_GEN4(f),  f(4)
# define FMT_GEN6(f)  FMT_GEN5(f),  f(5)
# define FMT_GEN7(f)  FMT_GEN6(f),  f(6)
# define FMT_GEN8(f)  FMT_GEN7(f),  f(7)
# define FMT_GEN9(f)  FMT_GEN8(f),  f(8)
# define FMT_GEN10(f) FMT_GEN9(f),  f(9)
# define FMT_GEN11(f) FMT_GEN10(f), f(10)
# define FMT_GEN12(f) FMT_GEN11(f), f(11)
# define FMT_GEN13(f) FMT_GEN12(f), f(12)
# define FMT_GEN14(f) FMT_GEN13(f), f(13)
# define FMT_GEN15(f) FMT_GEN14(f), f(14)

namespace internal {
inline uint64_t make_type() { return 0; }

template <typename T>
inline uint64_t make_type(const T &arg) { return MakeValue<char>::type(arg); }

#if FMT_USE_VARIADIC_TEMPLATES
template <typename Arg, typename... Args>
inline uint64_t make_type(const Arg &first, const Args & ... tail) {
  return make_type(first) | (make_type(tail...) << 4);
}
#else

struct ArgType {
  uint64_t type;

  ArgType() : type(0) {}

  template <typename T>
  ArgType(const T &arg) : type(make_type(arg)) {}
};

# define FMT_ARG_TYPE_DEFAULT(n) ArgType t##n = ArgType()

inline uint64_t make_type(FMT_GEN15(FMT_ARG_TYPE_DEFAULT)) {
  return t0.type | (t1.type << 4) | (t2.type << 8) | (t3.type << 12) |
      (t4.type << 16) | (t5.type << 20) | (t6.type << 24) | (t7.type << 28) |
      (t8.type << 32) | (t9.type << 36) | (t10.type << 40) | (t11.type << 44) |
      (t12.type << 48) | (t13.type << 52) | (t14.type << 56);
}
#endif
}  // namespace internal

# define FMT_MAKE_TEMPLATE_ARG(n) typename T##n
# define FMT_MAKE_ARG_TYPE(n) T##n
# define FMT_MAKE_ARG(n) const T##n &v##n
# define FMT_MAKE_REF_char(n) fmt::internal::MakeValue<char>(v##n)
# define FMT_MAKE_REF_wchar_t(n) fmt::internal::MakeValue<wchar_t>(v##n)

#if FMT_USE_VARIADIC_TEMPLATES
// Defines a variadic function returning void.
# define FMT_VARIADIC_VOID(func, arg_type) \
  template <typename... Args> \
  void func(arg_type arg1, const Args & ... args) { \
    const fmt::internal::Value values[ \
      fmt::internal::NonZero<sizeof...(Args)>::VALUE] = { \
      fmt::internal::MakeValue<Char>(args)... \
    }; \
    func(arg1, ArgList(fmt::internal::make_type(args...), values)); \
  }

// Defines a variadic constructor.
# define FMT_VARIADIC_CTOR(ctor, func, arg0_type, arg1_type) \
  template <typename... Args> \
  ctor(arg0_type arg0, arg1_type arg1, const Args & ... args) { \
    using fmt::internal::MakeValue; \
    const fmt::internal::Value values[ \
        fmt::internal::NonZero<sizeof...(Args)>::VALUE] = { \
      MakeValue<Char>(args)... \
    }; \
    func(arg0, arg1, ArgList(fmt::internal::make_type(args...), values)); \
  }

#else

# define FMT_MAKE_REF(n) fmt::internal::MakeValue<Char>(v##n)
# define FMT_MAKE_REF2(n) v##n

// Defines a wrapper for a function taking one argument of type arg_type
// and n additional arguments of arbitrary types.
# 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::Value vals[] = {FMT_GEN(n, FMT_MAKE_REF)}; \
    func(arg1, fmt::ArgList( \
      fmt::internal::make_type(FMT_GEN(n, FMT_MAKE_REF2)), vals)); \
  }

// Emulates a variadic function returning void on a pre-C++11 compiler.
# define FMT_VARIADIC_VOID(func, arg_type) \
  FMT_WRAP1(func, arg_type, 1) FMT_WRAP1(func, arg_type, 2) \
  FMT_WRAP1(func, arg_type, 3) FMT_WRAP1(func, arg_type, 4) \
  FMT_WRAP1(func, arg_type, 5) FMT_WRAP1(func, arg_type, 6) \
  FMT_WRAP1(func, arg_type, 7) FMT_WRAP1(func, arg_type, 8) \
  FMT_WRAP1(func, arg_type, 9) FMT_WRAP1(func, arg_type, 10)

# 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::Value vals[] = {FMT_GEN(n, FMT_MAKE_REF)}; \
    func(arg0, arg1, fmt::ArgList( \
      fmt::internal::make_type(FMT_GEN(n, FMT_MAKE_REF2)), vals)); \
  }

// Emulates a variadic constructor on a pre-C++11 compiler.
# define FMT_VARIADIC_CTOR(ctor, func, arg0_type, arg1_type) \
  FMT_CTOR(ctor, func, arg0_type, arg1_type, 1) \
  FMT_CTOR(ctor, func, arg0_type, arg1_type, 2) \
  FMT_CTOR(ctor, func, arg0_type, arg1_type, 3) \
  FMT_CTOR(ctor, func, arg0_type, arg1_type, 4) \
  FMT_CTOR(ctor, func, arg0_type, arg1_type, 5) \
  FMT_CTOR(ctor, func, arg0_type, arg1_type, 6) \
  FMT_CTOR(ctor, func, arg0_type, arg1_type, 7) \
  FMT_CTOR(ctor, func, arg0_type, arg1_type, 8) \
  FMT_CTOR(ctor, func, arg0_type, arg1_type, 9) \
  FMT_CTOR(ctor, func, arg0_type, arg1_type, 10)
#endif

// Generates a comma-separated list with results of applying f to pairs
// (argument, index).
#define FMT_FOR_EACH1(f, x0) f(x0, 0)
#define FMT_FOR_EACH2(f, x0, x1) \
  FMT_FOR_EACH1(f, x0), f(x1, 1)
#define FMT_FOR_EACH3(f, x0, x1, x2) \
  FMT_FOR_EACH2(f, x0 ,x1), f(x2, 2)
#define FMT_FOR_EACH4(f, x0, x1, x2, x3) \
  FMT_FOR_EACH3(f, x0, x1, x2), f(x3, 3)
#define FMT_FOR_EACH5(f, x0, x1, x2, x3, x4) \
  FMT_FOR_EACH4(f, x0, x1, x2, x3), f(x4, 4)
#define FMT_FOR_EACH6(f, x0, x1, x2, x3, x4, x5) \
  FMT_FOR_EACH5(f, x0, x1, x2, x3, x4), f(x5, 5)
#define FMT_FOR_EACH7(f, x0, x1, x2, x3, x4, x5, x6) \
  FMT_FOR_EACH6(f, x0, x1, x2, x3, x4, x5), f(x6, 6)
#define FMT_FOR_EACH8(f, x0, x1, x2, x3, x4, x5, x6, x7) \
  FMT_FOR_EACH7(f, x0, x1, x2, x3, x4, x5, x6), f(x7, 7)
#define FMT_FOR_EACH9(f, x0, x1, x2, x3, x4, x5, x6, x7, x8) \
  FMT_FOR_EACH8(f, x0, x1, x2, x3, x4, x5, x6, x7), f(x8, 8)
#define FMT_FOR_EACH10(f, x0, x1, x2, x3, x4, x5, x6, x7, x8, x9) \
  FMT_FOR_EACH9(f, x0, x1, x2, x3, x4, x5, x6, x7, x8), f(x9, 9)

/**
 An error returned by an operating system or a language runtime,
 for example a file opening error.
*/
class SystemError : public internal::RuntimeError {
 private:
  void init(int error_code, StringRef format_str, ArgList args);

 protected:
  int error_code_;

  typedef char Char;  // For FMT_VARIADIC_CTOR.

  SystemError() {}

 public:
  /**
   \rst
   Constructs a :cpp:class:`fmt::SystemError` object with the description
   of the form "*<message>*: *<system-message>*", where *<message>* is the
   formatted message and *<system-message>* is the system message corresponding
   to the error code.
   *error_code* is a system error code as given by ``errno``.
   \endrst
  */
  SystemError(int error_code, StringRef message) {
    init(error_code, message, ArgList());
  }
  FMT_VARIADIC_CTOR(SystemError, init, int, StringRef)

  int error_code() const { return error_code_; }
};

/**
  \rst
  This template provides operations for formatting and writing data into
  a character stream. The output is stored in a buffer provided by a subclass
  such as :cpp:class:`fmt::BasicMemoryWriter`.

  You can use one of the following typedefs for common character types:

  +---------+----------------------+
  | Type    | Definition           |
  +=========+======================+
  | Writer  | BasicWriter<char>    |
  +---------+----------------------+
  | WWriter | BasicWriter<wchar_t> |
  +---------+----------------------+

  \endrst
 */
template <typename Char>
class BasicWriter {
 private:
  // Output buffer.
  internal::Buffer<Char> &buffer_;

  FMT_DISALLOW_COPY_AND_ASSIGN(BasicWriter);

  typedef typename internal::CharTraits<Char>::CharPtr CharPtr;

#if _SECURE_SCL
  // Returns pointer value.
  static Char *get(CharPtr p) { return p.base(); }
#else
  static Char *get(Char *p) { return p; }
#endif

  // Fills the padding around the content and returns the pointer to the
  // content area.
  static CharPtr fill_padding(CharPtr buffer,
      unsigned total_size, std::size_t content_size, wchar_t fill);

  // Grows the buffer by n characters and returns a pointer to the newly
  // allocated area.
  CharPtr grow_buffer(std::size_t n) {
    std::size_t size = buffer_.size();
    buffer_.resize(size + n);
    return internal::make_ptr(&buffer_[size], n);
  }

  // Prepare a buffer for integer formatting.
  CharPtr prepare_int_buffer(unsigned num_digits,
      const EmptySpec &, const char *prefix, unsigned prefix_size) {
    unsigned size = prefix_size + num_digits;
    CharPtr p = grow_buffer(size);
    std::copy(prefix, prefix + prefix_size, p);
    return p + size - 1;
  }

  template <typename Spec>
  CharPtr prepare_int_buffer(unsigned num_digits,
    const Spec &spec, const char *prefix, unsigned prefix_size);

  // Formats an integer.
  template <typename T, typename Spec>
  void write_int(T value, Spec spec);

  // Formats a floating-point number (double or long double).
  template <typename T>
  void write_double(T value, const FormatSpec &spec);

  // Writes a formatted string.
  template <typename StrChar>
  CharPtr write_str(
      const StrChar *s, std::size_t size, const AlignSpec &spec);

  template <typename StrChar>
  void write_str(
      const internal::Arg::StringValue<StrChar> &str, const FormatSpec &spec);

  // This method is private to disallow writing a wide string to a
  // char stream and vice versa. If you want to print a wide string
  // as a pointer as std::ostream does, cast it to const void*.
  // Do not implement!
  void operator<<(typename internal::CharTraits<Char>::UnsupportedStrType);

  friend class internal::ArgFormatter<Char>;
  friend class internal::PrintfFormatter<Char>;

 protected:
  /**
    Constructs a ``BasicWriter`` object.
   */
  explicit BasicWriter(internal::Buffer<Char> &b) : buffer_(b) {}

 public:
  /**
    Destroys a ``BasicWriter`` object.
   */
  virtual ~BasicWriter() {}

  /**
    Returns the total number of characters written.
   */
  std::size_t size() const { return buffer_.size(); }

  /**
    Returns a pointer to the output buffer content. No terminating null
    character is appended.
   */
  const Char *data() const FMT_NOEXCEPT(true) { return &buffer_[0]; }

  /**
    Returns a pointer to the output buffer content with terminating null
    character appended.
   */
  const Char *c_str() const {
    std::size_t size = buffer_.size();
    buffer_.reserve(size + 1);
    buffer_[size] = '\0';
    return &buffer_[0];
  }

  /**
    Returns the content of the output buffer as an `std::string`.
   */
  std::basic_string<Char> str() const {
    return std::basic_string<Char>(&buffer_[0], buffer_.size());
  }

  /**
    \rst
    Writes formatted data.

    *args* is an argument list representing arbitrary arguments.

    **Example**::

       MemoryWriter out;
       out.write("Current point:\n");
       out.write("({:+f}, {:+f})", -3.14, 3.14);

    This will write the following output to the ``out`` object:

    .. code-block:: none

       Current point:
       (-3.140000, +3.140000)

    The output can be accessed using :meth:`data`, :meth:`c_str` or :meth:`str`
    methods.

    See also :ref:`syntax`.
    \endrst
   */
  void write(BasicStringRef<Char> format, ArgList args) {
    BasicFormatter<Char>(*this).format(format, args);
  }
  FMT_VARIADIC_VOID(write, BasicStringRef<Char>)

  BasicWriter &operator<<(int value) {
    return *this << IntFormatSpec<int>(value);
  }
  BasicWriter &operator<<(unsigned value) {
    return *this << IntFormatSpec<unsigned>(value);
  }
  BasicWriter &operator<<(long value) {
    return *this << IntFormatSpec<long>(value);
  }
  BasicWriter &operator<<(unsigned long value) {
    return *this << IntFormatSpec<unsigned long>(value);
  }
  BasicWriter &operator<<(LongLong value) {
    return *this << IntFormatSpec<LongLong>(value);
  }

  /**
    Formats *value* and writes it to the stream.
   */
  BasicWriter &operator<<(ULongLong value) {
    return *this << IntFormatSpec<ULongLong>(value);
  }

  BasicWriter &operator<<(double value) {
    write_double(value, FormatSpec());
    return *this;
  }

  /**
    Formats *value* using the general format for floating-point numbers
    (``'g'``) and writes it to the stream.
   */
  BasicWriter &operator<<(long double value) {
    write_double(value, FormatSpec());
    return *this;
  }

  /**
    Writes a character to the stream.
   */
  BasicWriter &operator<<(char value) {
    buffer_.push_back(value);
    return *this;
  }

  BasicWriter &operator<<(wchar_t value) {
    buffer_.push_back(internal::CharTraits<Char>::convert(value));
    return *this;
  }

  /**
    Writes *value* to the stream.
   */
  BasicWriter &operator<<(fmt::BasicStringRef<Char> value) {
    const Char *str = value.c_str();
    buffer_.append(str, str + value.size());
    return *this;
  }

  template <typename T, typename Spec, typename FillChar>
  BasicWriter &operator<<(IntFormatSpec<T, Spec, FillChar> spec) {
    internal::CharTraits<Char>::convert(FillChar());
    write_int(spec.value(), spec);
    return *this;
  }

  template <typename StrChar>
  BasicWriter &operator<<(const StrFormatSpec<StrChar> &spec) {
    const StrChar *s = spec.str();
    // TODO: error if fill is not convertible to Char
    write_str(s, std::char_traits<Char>::length(s), spec);
    return *this;
  }

  void clear() FMT_NOEXCEPT(true) { buffer_.clear(); }
};

template <typename Char>
template <typename StrChar>
typename BasicWriter<Char>::CharPtr BasicWriter<Char>::write_str(
      const StrChar *s, std::size_t size, const AlignSpec &spec) {
  CharPtr out = CharPtr();
  if (spec.width() > size) {
    out = grow_buffer(spec.width());
    Char fill = static_cast<Char>(spec.fill());
    if (spec.align() == ALIGN_RIGHT) {
      std::fill_n(out, spec.width() - size, fill);
      out += spec.width() - size;
    } else if (spec.align() == ALIGN_CENTER) {
      out = fill_padding(out, spec.width(), size, fill);
    } else {
      std::fill_n(out + size, spec.width() - size, fill);
    }
  } else {
    out = grow_buffer(size);
  }
  std::copy(s, s + size, out);
  return out;
}

template <typename Char>
typename BasicWriter<Char>::CharPtr
  BasicWriter<Char>::fill_padding(
    CharPtr buffer, unsigned total_size,
    std::size_t content_size, wchar_t fill) {
  std::size_t padding = total_size - content_size;
  std::size_t left_padding = padding / 2;
  Char fill_char = static_cast<Char>(fill);
  std::fill_n(buffer, left_padding, fill_char);
  buffer += left_padding;
  CharPtr content = buffer;
  std::fill_n(buffer + content_size, padding - left_padding, fill_char);
  return content;
}

template <typename Char>
template <typename Spec>
typename BasicWriter<Char>::CharPtr
  BasicWriter<Char>::prepare_int_buffer(
    unsigned num_digits, const Spec &spec,
    const char *prefix, unsigned prefix_size) {
  unsigned width = spec.width();
  Alignment align = spec.align();
  Char fill = static_cast<Char>(spec.fill());
  if (spec.precision() > static_cast<int>(num_digits)) {
    // Octal prefix '0' is counted as a digit, so ignore it if precision
    // is specified.
    if (prefix_size > 0 && prefix[prefix_size - 1] == '0')
      --prefix_size;
    unsigned number_size = prefix_size + spec.precision();
    AlignSpec subspec(number_size, '0', ALIGN_NUMERIC);
    if (number_size >= width)
      return prepare_int_buffer(num_digits, subspec, prefix, prefix_size);
    buffer_.reserve(width);
    unsigned fill_size = width - number_size;
    if (align != ALIGN_LEFT) {
      CharPtr p = grow_buffer(fill_size);
      std::fill(p, p + fill_size, fill);
    }
    CharPtr result = prepare_int_buffer(
        num_digits, subspec, prefix, prefix_size);
    if (align == ALIGN_LEFT) {
      CharPtr p = grow_buffer(fill_size);
      std::fill(p, p + fill_size, fill);
    }
    return result;
  }
  unsigned size = prefix_size + num_digits;
  if (width <= size) {
    CharPtr p = grow_buffer(size);
    std::copy(prefix, prefix + prefix_size, p);
    return p + size - 1;
  }
  CharPtr p = grow_buffer(width);
  CharPtr end = p + width;
  if (align == ALIGN_LEFT) {
    std::copy(prefix, prefix + prefix_size, p);
    p += size;
    std::fill(p, end, fill);
  } else if (align == ALIGN_CENTER) {
    p = fill_padding(p, width, size, fill);
    std::copy(prefix, prefix + prefix_size, p);
    p += size;
  } else {
    if (align == ALIGN_NUMERIC) {
      if (prefix_size != 0) {
        p = std::copy(prefix, prefix + prefix_size, p);
        size -= prefix_size;
      }
    } else {
      std::copy(prefix, prefix + prefix_size, end - size);
    }
    std::fill(p, end - size, fill);
    p = end;
  }
  return p - 1;
}

template <typename Char>
template <typename T, typename Spec>
void BasicWriter<Char>::write_int(T value, Spec spec) {
  unsigned prefix_size = 0;
  typedef typename internal::IntTraits<T>::MainType UnsignedType;
  UnsignedType abs_value = value;
  char prefix[4] = "";
  if (internal::is_negative(value)) {
    prefix[0] = '-';
    ++prefix_size;
    abs_value = 0 - abs_value;
  } else if (spec.flag(SIGN_FLAG)) {
    prefix[0] = spec.flag(PLUS_FLAG) ? '+' : ' ';
    ++prefix_size;
  }
  switch (spec.type()) {
  case 0: case 'd': {
    unsigned num_digits = internal::count_digits(abs_value);
    CharPtr p = prepare_int_buffer(
      num_digits, spec, prefix, prefix_size) + 1 - num_digits;
    internal::format_decimal(get(p), abs_value, num_digits);
    break;
  }
  case 'x': case 'X': {
    UnsignedType n = abs_value;
    if (spec.flag(HASH_FLAG)) {
      prefix[prefix_size++] = '0';
      prefix[prefix_size++] = spec.type();
    }
    unsigned num_digits = 0;
    do {
      ++num_digits;
    } while ((n >>= 4) != 0);
    Char *p = get(prepare_int_buffer(
      num_digits, spec, prefix, prefix_size));
    n = abs_value;
    const char *digits = spec.type() == 'x' ?
        "0123456789abcdef" : "0123456789ABCDEF";
    do {
      *p-- = digits[n & 0xf];
    } while ((n >>= 4) != 0);
    break;
  }
  case 'b': case 'B': {
    UnsignedType n = abs_value;
    if (spec.flag(HASH_FLAG)) {
      prefix[prefix_size++] = '0';
      prefix[prefix_size++] = spec.type();
    }
    unsigned num_digits = 0;
    do {
      ++num_digits;
    } while ((n >>= 1) != 0);
    Char *p = get(prepare_int_buffer(num_digits, spec, prefix, prefix_size));
    n = abs_value;
    do {
      *p-- = '0' + (n & 1);
    } while ((n >>= 1) != 0);
    break;
  }
  case 'o': {
    UnsignedType n = abs_value;
    if (spec.flag(HASH_FLAG))
      prefix[prefix_size++] = '0';
    unsigned num_digits = 0;
    do {
      ++num_digits;
    } while ((n >>= 3) != 0);
    Char *p = get(prepare_int_buffer(num_digits, spec, prefix, prefix_size));
    n = abs_value;
    do {
      *p-- = '0' + (n & 7);
    } while ((n >>= 3) != 0);
    break;
  }
  default:
    internal::report_unknown_type(
      spec.type(), spec.flag(CHAR_FLAG) ? "char" : "integer");
    break;
  }
}

template <typename Char>
template <typename T>
void BasicWriter<Char>::write_double(
    T value, const FormatSpec &spec) {
  // Check type.
  char type = spec.type();
  bool upper = false;
  switch (type) {
  case 0:
    type = 'g';
    break;
  case 'e': case 'f': case 'g': case 'a':
    break;
  case 'F':
#ifdef _MSC_VER
    // MSVC's printf doesn't support 'F'.
    type = 'f';
#endif
    // Fall through.
  case 'E': case 'G': case 'A':
    upper = true;
    break;
  default:
    internal::report_unknown_type(type, "double");
    break;
  }

  char sign = 0;
  // Use getsign instead of value < 0 because the latter is always
  // false for NaN.
  if (internal::getsign(static_cast<double>(value))) {
    sign = '-';
    value = -value;
  } else if (spec.flag(SIGN_FLAG)) {
    sign = spec.flag(PLUS_FLAG) ? '+' : ' ';
  }

  if (value != value) {
    // Format NaN ourselves because sprintf's output is not consistent
    // across platforms.
    std::size_t size = 4;
    const char *nan = upper ? " NAN" : " nan";
    if (!sign) {
      --size;
      ++nan;
    }
    CharPtr out = write_str(nan, size, spec);
    if (sign)
      *out = sign;
    return;
  }

  if (internal::isinfinity(value)) {
    // Format infinity ourselves because sprintf's output is not consistent
    // across platforms.
    std::size_t size = 4;
    const char *inf = upper ? " INF" : " inf";
    if (!sign) {
      --size;
      ++inf;
    }
    CharPtr out = write_str(inf, size, spec);
    if (sign)
      *out = sign;
    return;
  }

  std::size_t offset = buffer_.size();
  unsigned width = spec.width();
  if (sign) {
    buffer_.reserve(buffer_.size() + (std::max)(width, 1u));
    if (width > 0)
      --width;
    ++offset;
  }

  // Build format string.
  enum { MAX_FORMAT_SIZE = 10}; // longest format: %#-*.*Lg
  Char format[MAX_FORMAT_SIZE];
  Char *format_ptr = format;
  *format_ptr++ = '%';
  unsigned width_for_sprintf = width;
  if (spec.flag(HASH_FLAG))
    *format_ptr++ = '#';
  if (spec.align() == ALIGN_CENTER) {
    width_for_sprintf = 0;
  } else {
    if (spec.align() == ALIGN_LEFT)
      *format_ptr++ = '-';
    if (width != 0)
      *format_ptr++ = '*';
  }
  if (spec.precision() >= 0) {
    *format_ptr++ = '.';
    *format_ptr++ = '*';
  }
  if (internal::IsLongDouble<T>::VALUE)
    *format_ptr++ = 'L';
  *format_ptr++ = type;
  *format_ptr = '\0';

  // Format using snprintf.
  Char fill = static_cast<Char>(spec.fill());
  for (;;) {
    std::size_t size = buffer_.capacity() - offset;
#if _MSC_VER
    // MSVC's vsnprintf_s doesn't work with zero size, so reserve
    // space for at least one extra character to make the size non-zero.
    // Note that the buffer's capacity will increase by more than 1.
    if (size == 0) {
      buffer_.reserve(offset + 1);
      size = buffer_.capacity() - offset;
    }
#endif
    Char *start = &buffer_[offset];
    int n = internal::CharTraits<Char>::format_float(
        start, size, format, width_for_sprintf, spec.precision(), value);
    if (n >= 0 && offset + n < buffer_.capacity()) {
      if (sign) {
        if ((spec.align() != ALIGN_RIGHT && spec.align() != ALIGN_DEFAULT) ||
            *start != ' ') {
          *(start - 1) = sign;
          sign = 0;
        } else {
          *(start - 1) = fill;
        }
        ++n;
      }
      if (spec.align() == ALIGN_CENTER &&
          spec.width() > static_cast<unsigned>(n)) {
        unsigned width = spec.width();
        CharPtr p = grow_buffer(width);
        std::copy(p, p + n, p + (width - n) / 2);
        fill_padding(p, spec.width(), n, fill);
        return;
      }
      if (spec.fill() != ' ' || sign) {
        while (*start == ' ')
          *start++ = fill;
        if (sign)
          *(start - 1) = sign;
      }
      grow_buffer(n);
      return;
    }
    // If n is negative we ask to increase the capacity by at least 1,
    // but as std::vector, the buffer grows exponentially.
    buffer_.reserve(n >= 0 ? offset + n + 1 : buffer_.capacity() + 1);
  }
}

/**
  \rst
  This template provides operations for formatting and writing data into
  a character stream. The output is stored in a memory buffer that grows
  dynamically.

  You can use one of the following typedefs for common character types
  and the standard allocator:

  +---------------+-----------------------------------------------+
  | Type          | Definition                                    |
  +===============+===============================================+
  | MemoryWriter  | BasicWriter<char, std::allocator<char>>       |
  +---------------+-----------------------------------------------+
  | WMemoryWriter | BasicWriter<wchar_t, std::allocator<wchar_t>> |
  +---------------+-----------------------------------------------+

  **Example**::

     MemoryWriter out;
     out << "The answer is " << 42 << "\n";
     out.write("({:+f}, {:+f})", -3.14, 3.14);

  This will write the following output to the ``out`` object:

  .. code-block:: none

     The answer is 42
     (-3.140000, +3.140000)

  The output can be converted to an ``std::string`` with ``out.str()`` or
  accessed as a C string with ``out.c_str()``.
  \endrst
 */
template <typename Char, typename Allocator = std::allocator<Char> >
class BasicMemoryWriter : public BasicWriter<Char> {
 private:
  internal::MemoryBuffer<Char, internal::INLINE_BUFFER_SIZE, Allocator> buffer_;

 public:
  explicit BasicMemoryWriter(const Allocator& alloc = Allocator())
    : BasicWriter<Char>(buffer_), buffer_(alloc) {}

#if FMT_USE_RVALUE_REFERENCES
  /**
    Constructs a ``BasicMemoryWriter`` object moving the content of the other
    object to it.
   */
  BasicMemoryWriter(BasicMemoryWriter &&other)
    : BasicWriter<Char>(buffer_), buffer_(std::move(other.buffer_)) {
  }

  /**
    Moves the content of the other ``BasicMemoryWriter`` object to this one.
   */
  BasicMemoryWriter &operator=(BasicMemoryWriter &&other) {
    buffer_ = std::move(other.buffer_);
    return *this;
  }
#endif
};

typedef BasicMemoryWriter<char> MemoryWriter;
typedef BasicMemoryWriter<wchar_t> WMemoryWriter;

// Formats a value.
template <typename Char, typename T>
void format(BasicFormatter<Char> &f, const Char *&format_str, const T &value) {
  std::basic_ostringstream<Char> os;
  os << value;
  internal::Arg arg;
  internal::Value &arg_value = arg;
  std::basic_string<Char> str = os.str();
  arg_value = internal::MakeValue<Char>(str);
  arg.type = internal::Arg::STRING;
  format_str = f.format(format_str, arg);
}

// Reports a system error without throwing an exception.
// Can be used to report errors from destructors.
void report_system_error(int error_code, StringRef message) FMT_NOEXCEPT(true);

#ifdef _WIN32

/**
 A Windows error.
*/
class WindowsError : public SystemError {
 private:
  void init(int error_code, StringRef format_str, ArgList args);

 public:
  /**
   \rst
   Constructs a :cpp:class:`fmt::WindowsError` object with the description
   of the form "*<message>*: *<system-message>*", where *<message>* is the
   formatted message and *<system-message>* is the system message corresponding
   to the error code.
   *error_code* is a Windows error code as given by ``GetLastError``.
   \endrst
  */
  WindowsError(int error_code, StringRef message) {
    init(error_code, message, ArgList());
  }
  FMT_VARIADIC_CTOR(WindowsError, init, int, StringRef)
};

// Reports a Windows error without throwing an exception.
// Can be used to report errors from destructors.
void report_windows_error(int error_code, StringRef message) FMT_NOEXCEPT(true);

#endif

enum Color { BLACK, RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN, WHITE };

/**
  Formats a string and prints it to stdout using ANSI escape sequences
  to specify color (experimental).
  Example:
    PrintColored(fmt::RED, "Elapsed time: {0:.2f} seconds") << 1.23;
 */
void print_colored(Color c, StringRef format, ArgList args);

/**
  \rst
  Formats arguments and returns the result as a string.

  **Example**::

    std::string message = format("The answer is {}", 42);
  \endrst
*/
inline std::string format(StringRef format_str, ArgList args) {
  MemoryWriter w;
  w.write(format_str, args);
  return w.str();
}

inline std::wstring format(WStringRef format_str, ArgList args) {
  WMemoryWriter w;
  w.write(format_str, args);
  return w.str();
}

/**
  \rst
  Prints formatted data to the file *f*.

  **Example**::

    print(stderr, "Don't {}!", "panic");
  \endrst
 */
void print(std::FILE *f, StringRef format_str, ArgList args);

/**
  \rst
  Prints formatted data to ``stdout``.

  **Example**::

    print("Elapsed time: {0:.2f} seconds", 1.23);
  \endrst
 */
void print(StringRef format_str, ArgList args);

/**
  \rst
  Prints formatted data to the stream *os*.

  **Example**::

    print(cerr, "Don't {}!", "panic");
  \endrst
 */
void print(std::ostream &os, StringRef format_str, ArgList args);

template <typename Char>
void printf(BasicWriter<Char> &w, BasicStringRef<Char> format, ArgList args) {
  internal::PrintfFormatter<Char>().format(w, format, args);
}

/**
  \rst
  Formats arguments and returns the result as a string.

  **Example**::

    std::string message = fmt::sprintf("The answer is %d", 42);
  \endrst
*/
inline std::string sprintf(StringRef format, ArgList args) {
  MemoryWriter w;
  printf(w, format, args);
  return w.str();
}

/**
  \rst
  Prints formatted data to the file *f*.

  **Example**::

    fmt::fprintf(stderr, "Don't %s!", "panic");
  \endrst
 */
int fprintf(std::FILE *f, StringRef format, ArgList args);

/**
  \rst
  Prints formatted data to ``stdout``.

  **Example**::

    fmt::printf("Elapsed time: %.2f seconds", 1.23);
  \endrst
 */
inline int printf(StringRef format, ArgList args) {
  return fprintf(stdout, format, args);
}

/**
  Fast integer formatter.
 */
class FormatInt {
 private:
  // Buffer should be large enough to hold all digits (digits10 + 1),
  // a sign and a null character.
  enum {BUFFER_SIZE = std::numeric_limits<ULongLong>::digits10 + 3};
  mutable char buffer_[BUFFER_SIZE];
  char *str_;

  // Formats value in reverse and returns the number of digits.
  char *format_decimal(ULongLong value) {
    char *buffer_end = buffer_ + BUFFER_SIZE - 1;
    while (value >= 100) {
      // Integer division is slow so do it for a group of two digits instead
      // of for every digit. The idea comes from the talk by Alexandrescu
      // "Three Optimization Tips for C++". See speed-test for a comparison.
      unsigned index = (value % 100) * 2;
      value /= 100;
      *--buffer_end = internal::DIGITS[index + 1];
      *--buffer_end = internal::DIGITS[index];
    }
    if (value < 10) {
      *--buffer_end = static_cast<char>('0' + value);
      return buffer_end;
    }
    unsigned index = static_cast<unsigned>(value * 2);
    *--buffer_end = internal::DIGITS[index + 1];
    *--buffer_end = internal::DIGITS[index];
    return buffer_end;
  }

  void FormatSigned(LongLong value) {
    ULongLong abs_value = static_cast<ULongLong>(value);
    bool negative = value < 0;
    if (negative)
      abs_value = 0 - abs_value;
    str_ = format_decimal(abs_value);
    if (negative)
      *--str_ = '-';
  }

 public:
  explicit FormatInt(int value) { FormatSigned(value); }
  explicit FormatInt(long value) { FormatSigned(value); }
  explicit FormatInt(LongLong value) { FormatSigned(value); }
  explicit FormatInt(unsigned value) : str_(format_decimal(value)) {}
  explicit FormatInt(unsigned long value) : str_(format_decimal(value)) {}
  explicit FormatInt(ULongLong value) : str_(format_decimal(value)) {}

  /**
    Returns the number of characters written to the output buffer.
   */
  std::size_t size() const { return buffer_ - str_ + BUFFER_SIZE - 1; }

  /**
    Returns a pointer to the output buffer content. No terminating null
    character is appended.
   */
  const char *data() const { return str_; }

  /**
    Returns a pointer to the output buffer content with terminating null
    character appended.
   */
  const char *c_str() const {
    buffer_[BUFFER_SIZE - 1] = '\0';
    return str_;
  }

  /**
    Returns the content of the output buffer as an `std::string`.
   */
  std::string str() const { return std::string(str_, size()); }
};

// Formats a decimal integer value writing into buffer and returns
// a pointer to the end of the formatted string. This function doesn't
// write a terminating null character.
template <typename T>
inline void format_decimal(char *&buffer, T value) {
  typename internal::IntTraits<T>::MainType abs_value = value;
  if (internal::is_negative(value)) {
    *buffer++ = '-';
    abs_value = 0 - abs_value;
  }
  if (abs_value < 100) {
    if (abs_value < 10) {
      *buffer++ = static_cast<char>('0' + abs_value);
      return;
    }
    unsigned index = static_cast<unsigned>(abs_value * 2);
    *buffer++ = internal::DIGITS[index];
    *buffer++ = internal::DIGITS[index + 1];
    return;
  }
  unsigned num_digits = internal::count_digits(abs_value);
  internal::format_decimal(buffer, abs_value, num_digits);
  buffer += num_digits;
}
}

#if FMT_GCC_VERSION
// Use the system_header pragma to suppress warnings about variadic macros
// because suppressing -Wvariadic-macros with the diagnostic pragma doesn't
// work. It is used at the end because we want to suppress as little warnings
// as possible.
# pragma GCC system_header
#endif

// This is used to work around VC++ bugs in handling variadic macros.
#define FMT_EXPAND(args) args

// Returns the number of arguments.
// Based on https://groups.google.com/forum/#!topic/comp.std.c/d-6Mj5Lko_s.
#define FMT_NARG(...) FMT_NARG_(__VA_ARGS__, FMT_RSEQ_N())
#define FMT_NARG_(...) FMT_EXPAND(FMT_ARG_N(__VA_ARGS__))
#define FMT_ARG_N(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, N, ...) N
#define FMT_RSEQ_N() 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0

#define FMT_CONCAT(a, b) a##b
#define FMT_FOR_EACH_(N, f, ...) \
  FMT_EXPAND(FMT_CONCAT(FMT_FOR_EACH, N)(f, __VA_ARGS__))
#define FMT_FOR_EACH(f, ...) \
  FMT_EXPAND(FMT_FOR_EACH_(FMT_NARG(__VA_ARGS__), f, __VA_ARGS__))

#define FMT_ADD_ARG_NAME(type, index) type arg##index
#define FMT_GET_ARG_NAME(type, index) arg##index

#if FMT_USE_VARIADIC_TEMPLATES
# define FMT_VARIADIC_(Char, ReturnType, func, call, ...) \
  template <typename... Args> \
  ReturnType func(FMT_FOR_EACH(FMT_ADD_ARG_NAME, __VA_ARGS__), \
      const Args & ... args) { \
    using fmt::internal::Value; \
    const Value values[fmt::internal::NonZero<sizeof...(Args)>::VALUE] = { \
      fmt::internal::MakeValue<Char>(args)... \
    }; \
    call(FMT_FOR_EACH(FMT_GET_ARG_NAME, __VA_ARGS__), fmt::ArgList( \
      fmt::internal::make_type(args...), values)); \
  }
#else
// Defines a wrapper for a function taking __VA_ARGS__ arguments
// and n additional arguments of arbitrary types.
# define FMT_WRAP(Char, ReturnType, func, call, n, ...) \
  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::Value vals[] = {FMT_GEN(n, FMT_MAKE_REF_##Char)}; \
    call(FMT_FOR_EACH(FMT_GET_ARG_NAME, __VA_ARGS__), fmt::ArgList( \
      fmt::internal::make_type(FMT_GEN(n, FMT_MAKE_REF2)), vals)); \
  }

# define FMT_VARIADIC_(Char, ReturnType, func, call, ...) \
  inline ReturnType func(FMT_FOR_EACH(FMT_ADD_ARG_NAME, __VA_ARGS__)) { \
    call(FMT_FOR_EACH(FMT_GET_ARG_NAME, __VA_ARGS__), fmt::ArgList()); \
  } \
  FMT_WRAP(Char, ReturnType, func, call, 1, __VA_ARGS__) \
  FMT_WRAP(Char, ReturnType, func, call, 2, __VA_ARGS__) \
  FMT_WRAP(Char, ReturnType, func, call, 3, __VA_ARGS__) \
  FMT_WRAP(Char, ReturnType, func, call, 4, __VA_ARGS__) \
  FMT_WRAP(Char, ReturnType, func, call, 5, __VA_ARGS__) \
  FMT_WRAP(Char, ReturnType, func, call, 6, __VA_ARGS__) \
  FMT_WRAP(Char, ReturnType, func, call, 7, __VA_ARGS__) \
  FMT_WRAP(Char, ReturnType, func, call, 8, __VA_ARGS__) \
  FMT_WRAP(Char, ReturnType, func, call, 9, __VA_ARGS__) \
  FMT_WRAP(Char, ReturnType, func, call, 10, __VA_ARGS__) \
  FMT_WRAP(Char, ReturnType, func, call, 11, __VA_ARGS__) \
  FMT_WRAP(Char, ReturnType, func, call, 12, __VA_ARGS__) \
  FMT_WRAP(Char, ReturnType, func, call, 13, __VA_ARGS__) \
  FMT_WRAP(Char, ReturnType, func, call, 14, __VA_ARGS__) \
  FMT_WRAP(Char, ReturnType, func, call, 15, __VA_ARGS__)
#endif  // FMT_USE_VARIADIC_TEMPLATES

/**
  \rst
  Defines a variadic function with the specified return type, function name
  and argument types passed as variable arguments to this macro.

  **Example**::

    void print_error(const char *file, int line, const char *format,
                     fmt::ArgList args) {
      fmt::print("{}: {}: ", file, line);
      fmt::print(format, args);
    }
    FMT_VARIADIC(void, print_error, const char *, int, const char *)

  ``FMT_VARIADIC`` is used for compatibility with legacy C++ compilers that
  don't implement variadic templates. You don't have to use this macro if
  you don't need legacy compiler support and can use variadic templates
  directly::

    template <typename... Args>
    void print_error(const char *file, int line, const char *format,
                     const Args & ... args) {
      fmt::print("{}: {}: ", file, line);
      fmt::print(format, args...);
    }
  \endrst
 */
#define FMT_VARIADIC(ReturnType, func, ...) \
  FMT_VARIADIC_(char, ReturnType, func, return func, __VA_ARGS__)

#define FMT_VARIADIC_W(ReturnType, func, ...) \
  FMT_VARIADIC_(wchar_t, ReturnType, func, return func, __VA_ARGS__)

namespace fmt {
FMT_VARIADIC(std::string, format, StringRef)
FMT_VARIADIC_W(std::wstring, format, WStringRef)
FMT_VARIADIC(void, print, StringRef)
FMT_VARIADIC(void, print, std::FILE *, StringRef)
FMT_VARIADIC(void, print, std::ostream &, StringRef)
FMT_VARIADIC(void, print_colored, Color, StringRef)
FMT_VARIADIC(std::string, sprintf, StringRef)
FMT_VARIADIC(int, printf, StringRef)
FMT_VARIADIC(int, fprintf, std::FILE *, StringRef)
}

// Restore warnings.
#if FMT_GCC_VERSION >= 406
# pragma GCC diagnostic pop
#endif


} // end generic namespace

#endif  // FMT_FORMAT_HPP_