fmt library updated

ext/fmt/format.cc

@@ -0,0 +1,542 @@
+/*
+ Formatting library for C++
+
+ Copyright (c) 2012 - 2016, Victor Zverovich
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ 1. Redistributions of source code must retain the above copyright notice, this
+    list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright notice,
+    this list of conditions and the following disclaimer in the documentation
+    and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "format.h"
+
+#include <string.h>
+
+#include <cctype>
+#include <cerrno>
+#include <climits>
+#include <cmath>
+#include <cstdarg>
+#include <cstddef>  // for std::ptrdiff_t
+
+#if defined(_WIN32) && defined(__MINGW32__)
+# include <cstring>
+#endif
+
+#if FMT_USE_WINDOWS_H
+# if defined(NOMINMAX) || defined(FMT_WIN_MINMAX)
+#  include <windows.h>
+# else
+#  define NOMINMAX
+#  include <windows.h>
+#  undef NOMINMAX
+# endif
+#endif
+
+#if FMT_EXCEPTIONS
+# define FMT_TRY try
+# define FMT_CATCH(x) catch (x)
+#else
+# define FMT_TRY if (true)
+# define FMT_CATCH(x) if (false)
+#endif
+
+#ifdef _MSC_VER
+# pragma warning(push)
+# pragma warning(disable: 4127)  // conditional expression is constant
+# pragma warning(disable: 4702)  // unreachable code
+// Disable deprecation warning for strerror. The latter is not called but
+// MSVC fails to detect it.
+# pragma warning(disable: 4996)
+#endif
+
+// Dummy implementations of strerror_r and strerror_s called if corresponding
+// system functions are not available.
+static inline fmt::internal::Null<> strerror_r(int, char *, ...) {
+  return fmt::internal::Null<>();
+}
+static inline fmt::internal::Null<> strerror_s(char *, std::size_t, ...) {
+  return fmt::internal::Null<>();
+}
+
+namespace fmt {
+
+FMT_FUNC internal::RuntimeError::~RuntimeError() FMT_DTOR_NOEXCEPT {}
+FMT_FUNC FormatError::~FormatError() FMT_DTOR_NOEXCEPT {}
+FMT_FUNC SystemError::~SystemError() FMT_DTOR_NOEXCEPT {}
+
+namespace {
+
+#ifndef _MSC_VER
+# define FMT_SNPRINTF snprintf
+#else  // _MSC_VER
+inline int fmt_snprintf(char *buffer, size_t size, const char *format, ...) {
+  va_list args;
+  va_start(args, format);
+  int result = vsnprintf_s(buffer, size, _TRUNCATE, format, args);
+  va_end(args);
+  return result;
+}
+# define FMT_SNPRINTF fmt_snprintf
+#endif  // _MSC_VER
+
+#if defined(_WIN32) && defined(__MINGW32__) && !defined(__NO_ISOCEXT)
+# define FMT_SWPRINTF snwprintf
+#else
+# define FMT_SWPRINTF swprintf
+#endif // defined(_WIN32) && defined(__MINGW32__) && !defined(__NO_ISOCEXT)
+
+const char RESET_COLOR[] = "\x1b[0m";
+
+typedef void (*FormatFunc)(Writer &, int, StringRef);
+
+// Portable thread-safe version of strerror.
+// Sets buffer to point to a string describing the error code.
+// This can be either a pointer to a string stored in buffer,
+// or a pointer to some static immutable string.
+// Returns one of the following values:
+//   0      - success
+//   ERANGE - buffer is not large enough to store the error message
+//   other  - failure
+// Buffer should be at least of size 1.
+int safe_strerror(
+    int error_code, char *&buffer, std::size_t buffer_size) FMT_NOEXCEPT {
+  FMT_ASSERT(buffer != 0 && buffer_size != 0, "invalid buffer");
+
+  class StrError {
+   private:
+    int error_code_;
+    char *&buffer_;
+    std::size_t buffer_size_;
+
+    // A noop assignment operator to avoid bogus warnings.
+    void operator=(const StrError &) {}
+
+    // Handle the result of XSI-compliant version of strerror_r.
+    int handle(int result) {
+      // glibc versions before 2.13 return result in errno.
+      return result == -1 ? errno : result;
+    }
+
+    // Handle the result of GNU-specific version of strerror_r.
+    int handle(char *message) {
+      // If the buffer is full then the message is probably truncated.
+      if (message == buffer_ && strlen(buffer_) == buffer_size_ - 1)
+        return ERANGE;
+      buffer_ = message;
+      return 0;
+    }
+
+    // Handle the case when strerror_r is not available.
+    int handle(internal::Null<>) {
+      return fallback(strerror_s(buffer_, buffer_size_, error_code_));
+    }
+
+    // Fallback to strerror_s when strerror_r is not available.
+    int fallback(int result) {
+      // If the buffer is full then the message is probably truncated.
+      return result == 0 && strlen(buffer_) == buffer_size_ - 1 ?
+            ERANGE : result;
+    }
+
+    // Fallback to strerror if strerror_r and strerror_s are not available.
+    int fallback(internal::Null<>) {
+      errno = 0;
+      buffer_ = strerror(error_code_);
+      return errno;
+    }
+
+   public:
+    StrError(int err_code, char *&buf, std::size_t buf_size)
+      : error_code_(err_code), buffer_(buf), buffer_size_(buf_size) {}
+
+    int run() {
+      // Suppress a warning about unused strerror_r.
+      strerror_r(0, FMT_NULL, "");
+      return handle(strerror_r(error_code_, buffer_, buffer_size_));
+    }
+  };
+  return StrError(error_code, buffer, buffer_size).run();
+}
+
+void format_error_code(Writer &out, int error_code,
+                       StringRef message) FMT_NOEXCEPT {
+  // Report error code making sure that the output fits into
+  // INLINE_BUFFER_SIZE to avoid dynamic memory allocation and potential
+  // bad_alloc.
+  out.clear();
+  static const char SEP[] = ": ";
+  static const char ERROR_STR[] = "error ";
+  // Subtract 2 to account for terminating null characters in SEP and ERROR_STR.
+  std::size_t error_code_size = sizeof(SEP) + sizeof(ERROR_STR) - 2;
+  typedef internal::IntTraits<int>::MainType MainType;
+  MainType abs_value = static_cast<MainType>(error_code);
+  if (internal::is_negative(error_code)) {
+    abs_value = 0 - abs_value;
+    ++error_code_size;
+  }
+  error_code_size += internal::count_digits(abs_value);
+  if (message.size() <= internal::INLINE_BUFFER_SIZE - error_code_size)
+    out << message << SEP;
+  out << ERROR_STR << error_code;
+  assert(out.size() <= internal::INLINE_BUFFER_SIZE);
+}
+
+void report_error(FormatFunc func, int error_code,
+                  StringRef message) FMT_NOEXCEPT {
+  MemoryWriter full_message;
+  func(full_message, error_code, message);
+  // Use Writer::data instead of Writer::c_str to avoid potential memory
+  // allocation.
+  std::fwrite(full_message.data(), full_message.size(), 1, stderr);
+  std::fputc('\n', stderr);
+}
+}  // namespace
+
+namespace internal {
+
+// This method is used to preserve binary compatibility with fmt 3.0.
+// It can be removed in 4.0.
+FMT_FUNC void format_system_error(
+  Writer &out, int error_code, StringRef message) FMT_NOEXCEPT {
+  fmt::format_system_error(out, error_code, message);
+}
+}  // namespace internal
+
+FMT_FUNC void SystemError::init(
+    int err_code, CStringRef format_str, ArgList args) {
+  error_code_ = err_code;
+  MemoryWriter w;
+  format_system_error(w, err_code, format(format_str, args));
+  std::runtime_error &base = *this;
+  base = std::runtime_error(w.str());
+}
+
+template <typename T>
+int internal::CharTraits<char>::format_float(
+    char *buffer, std::size_t size, const char *format,
+    unsigned width, int precision, T value) {
+  if (width == 0) {
+    return precision < 0 ?
+        FMT_SNPRINTF(buffer, size, format, value) :
+        FMT_SNPRINTF(buffer, size, format, precision, value);
+  }
+  return precision < 0 ?
+      FMT_SNPRINTF(buffer, size, format, width, value) :
+      FMT_SNPRINTF(buffer, size, format, width, precision, value);
+}
+
+template <typename T>
+int internal::CharTraits<wchar_t>::format_float(
+    wchar_t *buffer, std::size_t size, const wchar_t *format,
+    unsigned width, int precision, T value) {
+  if (width == 0) {
+    return precision < 0 ?
+        FMT_SWPRINTF(buffer, size, format, value) :
+        FMT_SWPRINTF(buffer, size, format, precision, value);
+  }
+  return precision < 0 ?
+      FMT_SWPRINTF(buffer, size, format, width, value) :
+      FMT_SWPRINTF(buffer, size, format, width, precision, value);
+}
+
+template <typename T>
+const char internal::BasicData<T>::DIGITS[] =
+    "0001020304050607080910111213141516171819"
+    "2021222324252627282930313233343536373839"
+    "4041424344454647484950515253545556575859"
+    "6061626364656667686970717273747576777879"
+    "8081828384858687888990919293949596979899";
+
+#define FMT_POWERS_OF_10(factor) \
+  factor * 10, \
+  factor * 100, \
+  factor * 1000, \
+  factor * 10000, \
+  factor * 100000, \
+  factor * 1000000, \
+  factor * 10000000, \
+  factor * 100000000, \
+  factor * 1000000000
+
+template <typename T>
+const uint32_t internal::BasicData<T>::POWERS_OF_10_32[] = {
+  0, FMT_POWERS_OF_10(1)
+};
+
+template <typename T>
+const uint64_t internal::BasicData<T>::POWERS_OF_10_64[] = {
+  0,
+  FMT_POWERS_OF_10(1),
+  FMT_POWERS_OF_10(ULongLong(1000000000)),
+  // Multiply several constants instead of using a single long long constant
+  // to avoid warnings about C++98 not supporting long long.
+  ULongLong(1000000000) * ULongLong(1000000000) * 10
+};
+
+FMT_FUNC void internal::report_unknown_type(char code, const char *type) {
+  (void)type;
+  if (std::isprint(static_cast<unsigned char>(code))) {
+    FMT_THROW(FormatError(
+        format("unknown format code '{}' for {}", code, type)));
+  }
+  FMT_THROW(FormatError(
+      format("unknown format code '\\x{:02x}' for {}",
+        static_cast<unsigned>(code), type)));
+}
+
+#if FMT_USE_WINDOWS_H
+
+FMT_FUNC internal::UTF8ToUTF16::UTF8ToUTF16(StringRef s) {
+  static const char ERROR_MSG[] = "cannot convert string from UTF-8 to UTF-16";
+  if (s.size() > INT_MAX)
+    FMT_THROW(WindowsError(ERROR_INVALID_PARAMETER, ERROR_MSG));
+  int s_size = static_cast<int>(s.size());
+  int length = MultiByteToWideChar(
+      CP_UTF8, MB_ERR_INVALID_CHARS, s.data(), s_size, FMT_NULL, 0);
+  if (length == 0)
+    FMT_THROW(WindowsError(GetLastError(), ERROR_MSG));
+  buffer_.resize(length + 1);
+  length = MultiByteToWideChar(
+    CP_UTF8, MB_ERR_INVALID_CHARS, s.data(), s_size, &buffer_[0], length);
+  if (length == 0)
+    FMT_THROW(WindowsError(GetLastError(), ERROR_MSG));
+  buffer_[length] = 0;
+}
+
+FMT_FUNC internal::UTF16ToUTF8::UTF16ToUTF8(WStringRef s) {
+  if (int error_code = convert(s)) {
+    FMT_THROW(WindowsError(error_code,
+        "cannot convert string from UTF-16 to UTF-8"));
+  }
+}
+
+FMT_FUNC int internal::UTF16ToUTF8::convert(WStringRef s) {
+  if (s.size() > INT_MAX)
+    return ERROR_INVALID_PARAMETER;
+  int s_size = static_cast<int>(s.size());
+  int length = WideCharToMultiByte(
+    CP_UTF8, 0, s.data(), s_size, FMT_NULL, 0, FMT_NULL, FMT_NULL);
+  if (length == 0)
+    return GetLastError();
+  buffer_.resize(length + 1);
+  length = WideCharToMultiByte(
+    CP_UTF8, 0, s.data(), s_size, &buffer_[0], length, FMT_NULL, FMT_NULL);
+  if (length == 0)
+    return GetLastError();
+  buffer_[length] = 0;
+  return 0;
+}
+
+FMT_FUNC void WindowsError::init(
+    int err_code, CStringRef format_str, ArgList args) {
+  error_code_ = err_code;
+  MemoryWriter w;
+  internal::format_windows_error(w, err_code, format(format_str, args));
+  std::runtime_error &base = *this;
+  base = std::runtime_error(w.str());
+}
+
+FMT_FUNC void internal::format_windows_error(
+    Writer &out, int error_code, StringRef message) FMT_NOEXCEPT {
+  FMT_TRY {
+    MemoryBuffer<wchar_t, INLINE_BUFFER_SIZE> buffer;
+    buffer.resize(INLINE_BUFFER_SIZE);
+    for (;;) {
+      wchar_t *system_message = &buffer[0];
+      int result = FormatMessageW(
+        FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
+        FMT_NULL, error_code, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+        system_message, static_cast<uint32_t>(buffer.size()), FMT_NULL);
+      if (result != 0) {
+        UTF16ToUTF8 utf8_message;
+        if (utf8_message.convert(system_message) == ERROR_SUCCESS) {
+          out << message << ": " << utf8_message;
+          return;
+        }
+        break;
+      }
+      if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
+        break;  // Can't get error message, report error code instead.
+      buffer.resize(buffer.size() * 2);
+    }
+  } FMT_CATCH(...) {}
+  fmt::format_error_code(out, error_code, message);  // 'fmt::' is for bcc32.
+}
+
+#endif  // FMT_USE_WINDOWS_H
+
+FMT_FUNC void format_system_error(
+    Writer &out, int error_code, StringRef message) FMT_NOEXCEPT {
+  FMT_TRY {
+    internal::MemoryBuffer<char, internal::INLINE_BUFFER_SIZE> buffer;
+    buffer.resize(internal::INLINE_BUFFER_SIZE);
+    for (;;) {
+      char *system_message = &buffer[0];
+      int result = safe_strerror(error_code, system_message, buffer.size());
+      if (result == 0) {
+        out << message << ": " << system_message;
+        return;
+      }
+      if (result != ERANGE)
+        break;  // Can't get error message, report error code instead.
+      buffer.resize(buffer.size() * 2);
+    }
+  } FMT_CATCH(...) {}
+  fmt::format_error_code(out, error_code, message);  // 'fmt::' is for bcc32.
+}
+
+template <typename Char>
+void internal::ArgMap<Char>::init(const ArgList &args) {
+  if (!map_.empty())
+    return;
+  typedef internal::NamedArg<Char> NamedArg;
+  const NamedArg *named_arg = FMT_NULL;
+  bool use_values =
+      args.type(ArgList::MAX_PACKED_ARGS - 1) == internal::Arg::NONE;
+  if (use_values) {
+    for (unsigned i = 0;/*nothing*/; ++i) {
+      internal::Arg::Type arg_type = args.type(i);
+      switch (arg_type) {
+      case internal::Arg::NONE:
+        return;
+      case internal::Arg::NAMED_ARG:
+        named_arg = static_cast<const NamedArg*>(args.values_[i].pointer);
+        map_.push_back(Pair(named_arg->name, *named_arg));
+        break;
+      default:
+        /*nothing*/;
+      }
+    }
+    return;
+  }
+  for (unsigned i = 0; i != ArgList::MAX_PACKED_ARGS; ++i) {
+    internal::Arg::Type arg_type = args.type(i);
+    if (arg_type == internal::Arg::NAMED_ARG) {
+      named_arg = static_cast<const NamedArg*>(args.args_[i].pointer);
+      map_.push_back(Pair(named_arg->name, *named_arg));
+    }
+  }
+  for (unsigned i = ArgList::MAX_PACKED_ARGS;/*nothing*/; ++i) {
+    switch (args.args_[i].type) {
+    case internal::Arg::NONE:
+      return;
+    case internal::Arg::NAMED_ARG:
+      named_arg = static_cast<const NamedArg*>(args.args_[i].pointer);
+      map_.push_back(Pair(named_arg->name, *named_arg));
+      break;
+    default:
+      /*nothing*/;
+    }
+  }
+}
+
+template <typename Char>
+void internal::FixedBuffer<Char>::grow(std::size_t) {
+  FMT_THROW(std::runtime_error("buffer overflow"));
+}
+
+FMT_FUNC internal::Arg internal::FormatterBase::do_get_arg(
+    unsigned arg_index, const char *&error) {
+  internal::Arg arg = args_[arg_index];
+  switch (arg.type) {
+  case internal::Arg::NONE:
+    error = "argument index out of range";
+    break;
+  case internal::Arg::NAMED_ARG:
+    arg = *static_cast<const internal::Arg*>(arg.pointer);
+    break;
+  default:
+    /*nothing*/;
+  }
+  return arg;
+}
+
+FMT_FUNC void report_system_error(
+    int error_code, fmt::StringRef message) FMT_NOEXCEPT {
+  // 'fmt::' is for bcc32.
+  report_error(format_system_error, error_code, message);
+}
+
+#if FMT_USE_WINDOWS_H
+FMT_FUNC void report_windows_error(
+    int error_code, fmt::StringRef message) FMT_NOEXCEPT {
+  // 'fmt::' is for bcc32.
+  report_error(internal::format_windows_error, error_code, message);
+}
+#endif
+
+FMT_FUNC void print(std::FILE *f, CStringRef format_str, ArgList args) {
+  MemoryWriter w;
+  w.write(format_str, args);
+  std::fwrite(w.data(), 1, w.size(), f);
+}
+
+FMT_FUNC void print(CStringRef format_str, ArgList args) {
+  print(stdout, format_str, args);
+}
+
+FMT_FUNC void print_colored(Color c, CStringRef format, ArgList args) {
+  char escape[] = "\x1b[30m";
+  escape[3] = static_cast<char>('0' + c);
+  std::fputs(escape, stdout);
+  print(format, args);
+  std::fputs(RESET_COLOR, stdout);
+}
+
+#ifndef FMT_HEADER_ONLY
+
+template struct internal::BasicData<void>;
+
+// Explicit instantiations for char.
+
+template void internal::FixedBuffer<char>::grow(std::size_t);
+
+template void internal::ArgMap<char>::init(const ArgList &args);
+
+template FMT_API int internal::CharTraits<char>::format_float(
+    char *buffer, std::size_t size, const char *format,
+    unsigned width, int precision, double value);
+
+template FMT_API int internal::CharTraits<char>::format_float(
+    char *buffer, std::size_t size, const char *format,
+    unsigned width, int precision, long double value);
+
+// Explicit instantiations for wchar_t.
+
+template void internal::FixedBuffer<wchar_t>::grow(std::size_t);
+
+template void internal::ArgMap<wchar_t>::init(const ArgList &args);
+
+template FMT_API int internal::CharTraits<wchar_t>::format_float(
+    wchar_t *buffer, std::size_t size, const wchar_t *format,
+    unsigned width, int precision, double value);
+
+template FMT_API int internal::CharTraits<wchar_t>::format_float(
+    wchar_t *buffer, std::size_t size, const wchar_t *format,
+    unsigned width, int precision, long double value);
+
+#endif  // FMT_HEADER_ONLY
+
+}  // namespace fmt
+
+#ifdef _MSC_VER
+# pragma warning(pop)
+#endif

ext/fmt/ostream.cc

@@ -0,0 +1,35 @@
+/*
+ Formatting library for C++ - std::ostream support
+
+ Copyright (c) 2012 - 2016, Victor Zverovich
+ All rights reserved.
+
+ For the license information refer to format.h.
+ */
+
+#include "ostream.h"
+
+namespace fmt {
+
+namespace internal {
+FMT_FUNC void write(std::ostream &os, Writer &w) {
+  const char *data = w.data();
+  typedef internal::MakeUnsigned<std::streamsize>::Type UnsignedStreamSize;
+  UnsignedStreamSize size = w.size();
+  UnsignedStreamSize max_size =
+      internal::to_unsigned((std::numeric_limits<std::streamsize>::max)());
+  do {
+    UnsignedStreamSize n = size <= max_size ? size : max_size;
+    os.write(data, static_cast<std::streamsize>(n));
+    data += n;
+    size -= n;
+  } while (size != 0);
+}
+}
+
+FMT_FUNC void print(std::ostream &os, CStringRef format_str, ArgList args) {
+  MemoryWriter w;
+  w.write(format_str, args);
+  internal::write(os, w);
+}
+}  // namespace fmt

ext/fmt/ostream.h

@@ -0,0 +1,148 @@
+/*
+ Formatting library for C++ - std::ostream support
+
+ Copyright (c) 2012 - 2016, Victor Zverovich
+ All rights reserved.
+
+ For the license information refer to format.h.
+ */
+
+#ifndef FMT_OSTREAM_H_
+#define FMT_OSTREAM_H_
+
+#include "format.h"
+#include <ostream>
+
+namespace fmt {
+
+namespace internal {
+
+template <class Char>
+class FormatBuf : public std::basic_streambuf<Char> {
+ private:
+  typedef typename std::basic_streambuf<Char>::int_type int_type;
+  typedef typename std::basic_streambuf<Char>::traits_type traits_type;
+
+  Buffer<Char> &buffer_;
+  Char *start_;
+
+ public:
+  FormatBuf(Buffer<Char> &buffer) : buffer_(buffer), start_(&buffer[0]) {
+    this->setp(start_, start_ + buffer_.capacity());
+  }
+
+  FormatBuf(Buffer<Char> &buffer, Char *start) : buffer_(buffer) , start_(start) {
+    this->setp(start_, start_ + buffer_.capacity());
+  }
+
+  int_type overflow(int_type ch = traits_type::eof()) FMT_OVERRIDE {
+    if (!traits_type::eq_int_type(ch, traits_type::eof())) {
+      size_t buf_size = size();
+      buffer_.resize(buf_size);
+      buffer_.reserve(buf_size * 2);
+
+      start_ = &buffer_[0];
+      start_[buf_size] = traits_type::to_char_type(ch);
+      this->setp(start_+ buf_size + 1, start_ + buf_size * 2);
+    }
+    return ch;
+  }
+
+  size_t size() const {
+    return to_unsigned(this->pptr() - start_);
+  }
+};
+
+Yes &convert(std::ostream &);
+
+struct DummyStream : std::ostream {
+  DummyStream();  // Suppress a bogus warning in MSVC.
+  // Hide all operator<< overloads from std::ostream.
+  void operator<<(Null<>);
+};
+
+No &operator<<(std::ostream &, int);
+
+template<typename T>
+struct ConvertToIntImpl<T, true> {
+  // Convert to int only if T doesn't have an overloaded operator<<.
+  enum {
+    value = sizeof(convert(get<DummyStream>() << get<T>())) == sizeof(No)
+  };
+};
+
+// Write the content of w to os.
+void write(std::ostream &os, Writer &w);
+
+#if FMT_HAS_DECLTYPE_INCOMPLETE_RETURN_TYPES
+template<typename T>
+class is_streamable {
+  template<typename U>
+  static auto test(int) -> decltype(std::declval<std::ostream &>() << std::declval<U>(), std::true_type());
+
+  template<typename>
+  static auto test(...) -> std::false_type;
+
+public:
+  static constexpr bool value = decltype(test<T>(0))::value;
+};
+#endif
+}  // namespace internal
+
+// Formats a value.
+template <typename Char, typename ArgFormatter_, typename T>
+void format_arg(BasicFormatter<Char, ArgFormatter_> &f,
+                const Char *&format_str, const T &value) {
+  internal::MemoryBuffer<Char, internal::INLINE_BUFFER_SIZE> buffer;
+
+  internal::FormatBuf<Char> format_buf(buffer);
+  std::basic_ostream<Char> output(&format_buf);
+  output << value;
+
+  BasicStringRef<Char> str(&buffer[0], format_buf.size());
+  typedef internal::MakeArg< BasicFormatter<Char> > MakeArg;
+  format_str = f.format(format_str, MakeArg(str));
+}
+
+/**
+  \rst
+  Prints formatted data to the stream *os*.
+
+  **Example**::
+
+    print(cerr, "Don't {}!", "panic");
+  \endrst
+ */
+FMT_API void print(std::ostream &os, CStringRef format_str, ArgList args);
+FMT_VARIADIC(void, print, std::ostream &, CStringRef)
+
+#if __cplusplus >= 201103L
+template<typename T, typename Char>
+typename std::enable_if<
+ !std::is_same<
+   typename std::remove_cv<typename std::decay<T>::type>::type,
+   char *
+ >::value,
+ BasicWriter<Char>&
+>::type
+operator<<(BasicWriter<Char> &writer, const T &value) {
+  FMT_STATIC_ASSERT(internal::is_streamable<T>::value, "T must be Streamable");
+
+  auto &buffer = writer.buffer();
+  Char *start = &buffer[0] + buffer.size();
+
+  internal::FormatBuf<Char> format_buf(buffer, start);
+  std::basic_ostream<Char> output(&format_buf);
+  output << value;
+
+  buffer.resize(buffer.size() + format_buf.size());
+  return writer;
+}
+#endif
+}  // namespace fmt
+
+#ifdef FMT_HEADER_ONLY
+# include "ostream.cc"
+#endif
+
+#endif  // FMT_OSTREAM_H_