Add support for fmt/fmt::printf format

logger/bundled/fmt/printf.h

@@ -0,0 +1,855 @@
+// Formatting library for C++
+//
+// Copyright (c) 2012 - 2016, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_PRINTF_H_
+#define FMT_PRINTF_H_
+
+#include <algorithm>  // std::fill_n
+#include <limits>     // std::numeric_limits
+
+#include "ostream.h"
+
+FMT_BEGIN_NAMESPACE
+namespace internal {
+
+// An iterator that produces a null terminator on *end. This simplifies parsing
+// and allows comparing the performance of processing a null-terminated string
+// vs string_view.
+template <typename Char>
+class null_terminating_iterator {
+ public:
+  typedef std::ptrdiff_t difference_type;
+  typedef Char value_type;
+  typedef const Char* pointer;
+  typedef const Char& reference;
+  typedef std::random_access_iterator_tag iterator_category;
+
+  null_terminating_iterator() : ptr_(0), end_(0) {}
+
+  FMT_CONSTEXPR null_terminating_iterator(const Char *ptr, const Char *end)
+    : ptr_(ptr), end_(end) {}
+
+  template <typename Range>
+  FMT_CONSTEXPR explicit null_terminating_iterator(const Range &r)
+    : ptr_(r.begin()), end_(r.end()) {}
+
+  FMT_CONSTEXPR null_terminating_iterator &operator=(const Char *ptr) {
+    assert(ptr <= end_);
+    ptr_ = ptr;
+    return *this;
+  }
+
+  FMT_CONSTEXPR Char operator*() const {
+    return ptr_ != end_ ? *ptr_ : Char();
+  }
+
+  FMT_CONSTEXPR null_terminating_iterator operator++() {
+    ++ptr_;
+    return *this;
+  }
+
+  FMT_CONSTEXPR null_terminating_iterator operator++(int) {
+    null_terminating_iterator result(*this);
+    ++ptr_;
+    return result;
+  }
+
+  FMT_CONSTEXPR null_terminating_iterator operator--() {
+    --ptr_;
+    return *this;
+  }
+
+  FMT_CONSTEXPR null_terminating_iterator operator+(difference_type n) {
+    return null_terminating_iterator(ptr_ + n, end_);
+  }
+
+  FMT_CONSTEXPR null_terminating_iterator operator-(difference_type n) {
+    return null_terminating_iterator(ptr_ - n, end_);
+  }
+
+  FMT_CONSTEXPR null_terminating_iterator operator+=(difference_type n) {
+    ptr_ += n;
+    return *this;
+  }
+
+  FMT_CONSTEXPR difference_type operator-(
+      null_terminating_iterator other) const {
+    return ptr_ - other.ptr_;
+  }
+
+  FMT_CONSTEXPR bool operator!=(null_terminating_iterator other) const {
+    return ptr_ != other.ptr_;
+  }
+
+  bool operator>=(null_terminating_iterator other) const {
+    return ptr_ >= other.ptr_;
+  }
+
+  // This should be a friend specialization pointer_from<Char> but the latter
+  // doesn't compile by gcc 5.1 due to a compiler bug.
+  template <typename CharT>
+  friend FMT_CONSTEXPR_DECL const CharT *pointer_from(
+      null_terminating_iterator<CharT> it);
+
+ private:
+  const Char *ptr_;
+  const Char *end_;
+};
+
+template <typename T>
+FMT_CONSTEXPR const T *pointer_from(const T *p) { return p; }
+
+template <typename Char>
+FMT_CONSTEXPR const Char *pointer_from(null_terminating_iterator<Char> it) {
+  return it.ptr_;
+}
+
+// DEPRECATED: Parses the input as an unsigned integer. This function assumes
+// that the first character is a digit and presence of a non-digit character at
+// the end.
+// it: an iterator pointing to the beginning of the input range.
+template <typename Iterator, typename ErrorHandler>
+FMT_CONSTEXPR unsigned parse_nonnegative_int(Iterator &it, ErrorHandler &&eh) {
+  assert('0' <= *it && *it <= '9');
+  if (*it == '0') {
+    ++it;
+    return 0;
+  }
+  unsigned value = 0;
+  // Convert to unsigned to prevent a warning.
+  unsigned max_int = (std::numeric_limits<int>::max)();
+  unsigned big = max_int / 10;
+  do {
+    // Check for overflow.
+    if (value > big) {
+      value = max_int + 1;
+      break;
+    }
+    value = value * 10 + unsigned(*it - '0');
+    // Workaround for MSVC "setup_exception stack overflow" error:
+    auto next = it;
+    ++next;
+    it = next;
+  } while ('0' <= *it && *it <= '9');
+  if (value > max_int)
+    eh.on_error("number is too big");
+  return value;
+}
+
+// Checks if a value fits in int - used to avoid warnings about comparing
+// signed and unsigned integers.
+template <bool IsSigned>
+struct int_checker {
+  template <typename T>
+  static bool fits_in_int(T value) {
+    unsigned max = std::numeric_limits<int>::max();
+    return value <= max;
+  }
+  static bool fits_in_int(bool) { return true; }
+};
+
+template <>
+struct int_checker<true> {
+  template <typename T>
+  static bool fits_in_int(T value) {
+    return value >= std::numeric_limits<int>::min() &&
+           value <= std::numeric_limits<int>::max();
+  }
+  static bool fits_in_int(int) { return true; }
+};
+
+class printf_precision_handler: public function<int> {
+ public:
+  template <typename T>
+  typename std::enable_if<std::is_integral<T>::value, int>::type
+      operator()(T value) {
+    if (!int_checker<std::numeric_limits<T>::is_signed>::fits_in_int(value))
+      FMT_THROW(format_error("number is too big"));
+    return static_cast<int>(value);
+  }
+
+  template <typename T>
+  typename std::enable_if<!std::is_integral<T>::value, int>::type operator()(T) {
+    FMT_THROW(format_error("precision is not integer"));
+    return 0;
+  }
+};
+
+// An argument visitor that returns true iff arg is a zero integer.
+class is_zero_int: public function<bool> {
+ public:
+  template <typename T>
+  typename std::enable_if<std::is_integral<T>::value, bool>::type
+      operator()(T value) { return value == 0; }
+
+  template <typename T>
+  typename std::enable_if<!std::is_integral<T>::value, bool>::type
+      operator()(T) { return false; }
+};
+
+template <typename T>
+struct make_unsigned_or_bool : std::make_unsigned<T> {};
+
+template <>
+struct make_unsigned_or_bool<bool> {
+  typedef bool type;
+};
+
+template <typename T, typename Context>
+class arg_converter: public function<void> {
+ private:
+  typedef typename Context::char_type Char;
+
+  basic_format_arg<Context> &arg_;
+  typename Context::char_type type_;
+
+ public:
+  arg_converter(basic_format_arg<Context> &arg, Char type)
+    : arg_(arg), type_(type) {}
+
+  void operator()(bool value) {
+    if (type_ != 's')
+      operator()<bool>(value);
+  }
+
+  template <typename U>
+  typename std::enable_if<std::is_integral<U>::value>::type
+      operator()(U value) {
+    bool is_signed = type_ == 'd' || type_ == 'i';
+    typedef typename std::conditional<
+        std::is_same<T, void>::value, U, T>::type TargetType;
+    if (const_check(sizeof(TargetType) <= sizeof(int))) {
+      // Extra casts are used to silence warnings.
+      if (is_signed) {
+        arg_ = internal::make_arg<Context>(
+          static_cast<int>(static_cast<TargetType>(value)));
+      } else {
+        typedef typename make_unsigned_or_bool<TargetType>::type Unsigned;
+        arg_ = internal::make_arg<Context>(
+          static_cast<unsigned>(static_cast<Unsigned>(value)));
+      }
+    } else {
+      if (is_signed) {
+        // glibc's printf doesn't sign extend arguments of smaller types:
+        //   std::printf("%lld", -42);  // prints "4294967254"
+        // but we don't have to do the same because it's a UB.
+        arg_ = internal::make_arg<Context>(static_cast<long long>(value));
+      } else {
+        arg_ = internal::make_arg<Context>(
+          static_cast<typename make_unsigned_or_bool<U>::type>(value));
+      }
+    }
+  }
+
+  template <typename U>
+  typename std::enable_if<!std::is_integral<U>::value>::type operator()(U) {
+    // No coversion needed for non-integral types.
+  }
+};
+
+// Converts an integer argument to T for printf, if T is an integral type.
+// If T is void, the argument is converted to corresponding signed or unsigned
+// type depending on the type specifier: 'd' and 'i' - signed, other -
+// unsigned).
+template <typename T, typename Context, typename Char>
+void convert_arg(basic_format_arg<Context> &arg, Char type) {
+  visit_format_arg(arg_converter<T, Context>(arg, type), arg);
+}
+
+// Converts an integer argument to char for printf.
+template <typename Context>
+class char_converter: public function<void> {
+ private:
+  basic_format_arg<Context> &arg_;
+
+ public:
+  explicit char_converter(basic_format_arg<Context> &arg) : arg_(arg) {}
+
+  template <typename T>
+  typename std::enable_if<std::is_integral<T>::value>::type
+      operator()(T value) {
+    typedef typename Context::char_type Char;
+    arg_ = internal::make_arg<Context>(static_cast<Char>(value));
+  }
+
+  template <typename T>
+  typename std::enable_if<!std::is_integral<T>::value>::type operator()(T) {
+    // No coversion needed for non-integral types.
+  }
+};
+
+// Checks if an argument is a valid printf width specifier and sets
+// left alignment if it is negative.
+template <typename Char>
+class printf_width_handler: public function<unsigned> {
+ private:
+  typedef basic_format_specs<Char> format_specs;
+
+  format_specs &spec_;
+
+ public:
+  explicit printf_width_handler(format_specs &spec) : spec_(spec) {}
+
+  template <typename T>
+  typename std::enable_if<std::is_integral<T>::value, unsigned>::type
+      operator()(T value) {
+    typedef typename internal::int_traits<T>::main_type UnsignedType;
+    UnsignedType width = static_cast<UnsignedType>(value);
+    if (internal::is_negative(value)) {
+      spec_.align_ = ALIGN_LEFT;
+      width = 0 - width;
+    }
+    unsigned int_max = std::numeric_limits<int>::max();
+    if (width > int_max)
+      FMT_THROW(format_error("number is too big"));
+    return static_cast<unsigned>(width);
+  }
+
+  template <typename T>
+  typename std::enable_if<!std::is_integral<T>::value, unsigned>::type
+      operator()(T) {
+    FMT_THROW(format_error("width is not integer"));
+    return 0;
+  }
+};
+
+template <typename Char, typename Context>
+void printf(basic_buffer<Char> &buf, basic_string_view<Char> format,
+            basic_format_args<Context> args) {
+  Context(std::back_inserter(buf), format, args).format();
+}
+}  // namespace internal
+
+using internal::printf;  // For printing into memory_buffer.
+
+template <typename Range>
+class printf_arg_formatter;
+
+template <
+    typename OutputIt, typename Char,
+    typename ArgFormatter =
+      printf_arg_formatter<back_insert_range<internal::basic_buffer<Char>>>>
+class basic_printf_context;
+
+/**
+  \rst
+  The ``printf`` argument formatter.
+  \endrst
+ */
+template <typename Range>
+class printf_arg_formatter:
+  public internal::function<
+    typename internal::arg_formatter_base<Range>::iterator>,
+  public internal::arg_formatter_base<Range> {
+ private:
+  typedef typename Range::value_type char_type;
+  typedef decltype(internal::declval<Range>().begin()) iterator;
+  typedef internal::arg_formatter_base<Range> base;
+  typedef basic_printf_context<iterator, char_type> context_type;
+
+  context_type &context_;
+
+  void write_null_pointer(char) {
+    this->spec()->type = 0;
+    this->write("(nil)");
+  }
+
+  void write_null_pointer(wchar_t) {
+    this->spec()->type = 0;
+    this->write(L"(nil)");
+  }
+
+ public:
+  typedef typename base::format_specs format_specs;
+
+  /**
+    \rst
+    Constructs an argument formatter object.
+    *buffer* is a reference to the output buffer and *spec* contains format
+    specifier information for standard argument types.
+    \endrst
+   */
+  printf_arg_formatter(internal::basic_buffer<char_type> &buffer,
+                       format_specs &spec, context_type &ctx)
+    : base(back_insert_range<internal::basic_buffer<char_type>>(buffer), &spec,
+           ctx.locale()),
+      context_(ctx) {}
+
+  template <typename T>
+  typename std::enable_if<std::is_integral<T>::value, iterator>::type
+      operator()(T value) {
+    // MSVC2013 fails to compile separate overloads for bool and char_type so
+    // use std::is_same instead.
+    if (std::is_same<T, bool>::value) {
+      format_specs &fmt_spec = *this->spec();
+      if (fmt_spec.type != 's')
+        return base::operator()(value ? 1 : 0);
+      fmt_spec.type = 0;
+      this->write(value != 0);
+    } else if (std::is_same<T, char_type>::value) {
+      format_specs &fmt_spec = *this->spec();
+      if (fmt_spec.type && fmt_spec.type != 'c')
+        return (*this)(static_cast<int>(value));
+      fmt_spec.flags = 0;
+      fmt_spec.align_ = ALIGN_RIGHT;
+      return base::operator()(value);
+    } else {
+      return base::operator()(value);
+    }
+    return this->out();
+  }
+
+  template <typename T>
+  typename std::enable_if<std::is_floating_point<T>::value, iterator>::type
+      operator()(T value) {
+    return base::operator()(value);
+  }
+
+  /** Formats a null-terminated C string. */
+  iterator operator()(const char *value) {
+    if (value)
+      base::operator()(value);
+    else if (this->spec()->type == 'p')
+      write_null_pointer(char_type());
+    else
+      this->write("(null)");
+    return this->out();
+  }
+
+  /** Formats a null-terminated wide C string. */
+  iterator operator()(const wchar_t *value) {
+    if (value)
+      base::operator()(value);
+    else if (this->spec()->type == 'p')
+      write_null_pointer(char_type());
+    else
+      this->write(L"(null)");
+    return this->out();
+  }
+
+  iterator operator()(basic_string_view<char_type> value) {
+    return base::operator()(value);
+  }
+
+  iterator operator()(monostate value) {
+    return base::operator()(value);
+  }
+
+  /** Formats a pointer. */
+  iterator operator()(const void *value) {
+    if (value)
+      return base::operator()(value);
+    this->spec()->type = 0;
+    write_null_pointer(char_type());
+    return this->out();
+  }
+
+  /** Formats an argument of a custom (user-defined) type. */
+  iterator operator()(typename basic_format_arg<context_type>::handle handle) {
+    handle.format(context_);
+    return this->out();
+  }
+};
+
+template <typename T>
+struct printf_formatter {
+  template <typename ParseContext>
+  auto parse(ParseContext &ctx) -> decltype(ctx.begin()) { return ctx.begin(); }
+
+  template <typename FormatContext>
+  auto format(const T &value, FormatContext &ctx) -> decltype(ctx.out()) {
+    internal::format_value(internal::get_container(ctx.out()), value);
+    return ctx.out();
+  }
+};
+
+/** This template formats data and writes the output to a writer. */
+template <typename OutputIt, typename Char, typename ArgFormatter>
+class basic_printf_context :
+  // Inherit publicly as a workaround for the icc bug
+  // https://software.intel.com/en-us/forums/intel-c-compiler/topic/783476.
+  public internal::context_base<
+    OutputIt, basic_printf_context<OutputIt, Char, ArgFormatter>, Char> {
+ public:
+  /** The character type for the output. */
+  typedef Char char_type;
+
+  template <typename T>
+  struct formatter_type { typedef printf_formatter<T> type; };
+
+ private:
+  typedef internal::context_base<OutputIt, basic_printf_context, Char> base;
+  typedef typename base::format_arg format_arg;
+  typedef basic_format_specs<char_type> format_specs;
+  typedef internal::null_terminating_iterator<char_type> iterator;
+
+  void parse_flags(format_specs &spec, iterator &it);
+
+  // Returns the argument with specified index or, if arg_index is equal
+  // to the maximum unsigned value, the next argument.
+  format_arg get_arg(
+      iterator it,
+      unsigned arg_index = (std::numeric_limits<unsigned>::max)());
+
+  // Parses argument index, flags and width and returns the argument index.
+  unsigned parse_header(iterator &it, format_specs &spec);
+
+ public:
+  /**
+   \rst
+   Constructs a ``printf_context`` object. References to the arguments and
+   the writer are stored in the context object so make sure they have
+   appropriate lifetimes.
+   \endrst
+   */
+  basic_printf_context(OutputIt out, basic_string_view<char_type> format_str,
+                       basic_format_args<basic_printf_context> args)
+    : base(out, format_str, args) {}
+
+  using base::parse_context;
+  using base::out;
+  using base::advance_to;
+
+  /** Formats stored arguments and writes the output to the range. */
+  void format();
+};
+
+template <typename OutputIt, typename Char, typename AF>
+void basic_printf_context<OutputIt, Char, AF>::parse_flags(
+    format_specs &spec, iterator &it) {
+  for (;;) {
+    switch (*it++) {
+      case '-':
+        spec.align_ = ALIGN_LEFT;
+        break;
+      case '+':
+        spec.flags |= SIGN_FLAG | PLUS_FLAG;
+        break;
+      case '0':
+        spec.fill_ = '0';
+        break;
+      case ' ':
+        spec.flags |= SIGN_FLAG;
+        break;
+      case '#':
+        spec.flags |= HASH_FLAG;
+        break;
+      default:
+        --it;
+        return;
+    }
+  }
+}
+
+template <typename OutputIt, typename Char, typename AF>
+typename basic_printf_context<OutputIt, Char, AF>::format_arg
+  basic_printf_context<OutputIt, Char, AF>::get_arg(
+    iterator it, unsigned arg_index) {
+  (void)it;
+  if (arg_index == std::numeric_limits<unsigned>::max())
+    return this->do_get_arg(this->parse_context().next_arg_id());
+  return base::get_arg(arg_index - 1);
+}
+
+template <typename OutputIt, typename Char, typename AF>
+unsigned basic_printf_context<OutputIt, Char, AF>::parse_header(
+  iterator &it, format_specs &spec) {
+  unsigned arg_index = std::numeric_limits<unsigned>::max();
+  char_type c = *it;
+  if (c >= '0' && c <= '9') {
+    // Parse an argument index (if followed by '$') or a width possibly
+    // preceded with '0' flag(s).
+    internal::error_handler eh;
+    unsigned value = parse_nonnegative_int(it, eh);
+    if (*it == '$') {  // value is an argument index
+      ++it;
+      arg_index = value;
+    } else {
+      if (c == '0')
+        spec.fill_ = '0';
+      if (value != 0) {
+        // Nonzero value means that we parsed width and don't need to
+        // parse it or flags again, so return now.
+        spec.width_ = value;
+        return arg_index;
+      }
+    }
+  }
+  parse_flags(spec, it);
+  // Parse width.
+  if (*it >= '0' && *it <= '9') {
+    internal::error_handler eh;
+    spec.width_ = parse_nonnegative_int(it, eh);
+  } else if (*it == '*') {
+    ++it;
+    spec.width_ = visit_format_arg(
+          internal::printf_width_handler<char_type>(spec), get_arg(it));
+  }
+  return arg_index;
+}
+
+template <typename OutputIt, typename Char, typename AF>
+void basic_printf_context<OutputIt, Char, AF>::format() {
+  auto &buffer = internal::get_container(this->out());
+  auto start = iterator(this->parse_context());
+  auto it = start;
+  using internal::pointer_from;
+  while (*it) {
+    char_type c = *it++;
+    if (c != '%') continue;
+    if (*it == c) {
+      buffer.append(pointer_from(start), pointer_from(it));
+      start = ++it;
+      continue;
+    }
+    buffer.append(pointer_from(start), pointer_from(it) - 1);
+
+    format_specs spec;
+    spec.align_ = ALIGN_RIGHT;
+
+    // Parse argument index, flags and width.
+    unsigned arg_index = parse_header(it, spec);
+
+    // Parse precision.
+    if (*it == '.') {
+      ++it;
+      if ('0' <= *it && *it <= '9') {
+        internal::error_handler eh;
+        spec.precision = static_cast<int>(parse_nonnegative_int(it, eh));
+      } else if (*it == '*') {
+        ++it;
+        spec.precision =
+            visit_format_arg(internal::printf_precision_handler(), get_arg(it));
+      } else {
+        spec.precision = 0;
+      }
+    }
+
+    format_arg arg = get_arg(it, arg_index);
+    if (spec.has(HASH_FLAG) && visit_format_arg(internal::is_zero_int(), arg))
+      spec.flags = static_cast<uint_least8_t>(spec.flags & (~internal::to_unsigned<int>(HASH_FLAG)));
+    if (spec.fill_ == '0') {
+      if (arg.is_arithmetic())
+        spec.align_ = ALIGN_NUMERIC;
+      else
+        spec.fill_ = ' ';  // Ignore '0' flag for non-numeric types.
+    }
+
+    // Parse length and convert the argument to the required type.
+    using internal::convert_arg;
+    switch (*it++) {
+    case 'h':
+      if (*it == 'h')
+        convert_arg<signed char>(arg, *++it);
+      else
+        convert_arg<short>(arg, *it);
+      break;
+    case 'l':
+      if (*it == 'l')
+        convert_arg<long long>(arg, *++it);
+      else
+        convert_arg<long>(arg, *it);
+      break;
+    case 'j':
+      convert_arg<intmax_t>(arg, *it);
+      break;
+    case 'z':
+      convert_arg<std::size_t>(arg, *it);
+      break;
+    case 't':
+      convert_arg<std::ptrdiff_t>(arg, *it);
+      break;
+    case 'L':
+      // printf produces garbage when 'L' is omitted for long double, no
+      // need to do the same.
+      break;
+    default:
+      --it;
+      convert_arg<void>(arg, *it);
+    }
+
+    // Parse type.
+    if (!*it)
+      FMT_THROW(format_error("invalid format string"));
+    spec.type = static_cast<char>(*it++);
+    if (arg.is_integral()) {
+      // Normalize type.
+      switch (spec.type) {
+      case 'i': case 'u':
+        spec.type = 'd';
+        break;
+      case 'c':
+        // TODO: handle wchar_t better?
+        visit_format_arg(
+              internal::char_converter<basic_printf_context>(arg), arg);
+        break;
+      }
+    }
+
+    start = it;
+
+    // Format argument.
+    visit_format_arg(AF(buffer, spec, *this), arg);
+  }
+  buffer.append(pointer_from(start), pointer_from(it));
+}
+
+template <typename Buffer>
+struct basic_printf_context_t {
+  typedef basic_printf_context<
+    std::back_insert_iterator<Buffer>, typename Buffer::value_type> type;
+};
+
+typedef basic_printf_context_t<internal::buffer>::type printf_context;
+typedef basic_printf_context_t<internal::wbuffer>::type wprintf_context;
+
+typedef basic_format_args<printf_context> printf_args;
+typedef basic_format_args<wprintf_context> wprintf_args;
+
+/**
+  \rst
+  Constructs an `~fmt::format_arg_store` object that contains references to
+  arguments and can be implicitly converted to `~fmt::printf_args`. 
+  \endrst
+ */
+template<typename... Args>
+inline format_arg_store<printf_context, Args...>
+  make_printf_args(const Args &... args) { return {args...}; }
+
+/**
+  \rst
+  Constructs an `~fmt::format_arg_store` object that contains references to
+  arguments and can be implicitly converted to `~fmt::wprintf_args`. 
+  \endrst
+ */
+template<typename... Args>
+inline format_arg_store<wprintf_context, Args...>
+  make_wprintf_args(const Args &... args) { return {args...}; }
+
+template <typename S, typename Char = FMT_CHAR(S)>
+inline std::basic_string<Char>
+vsprintf(const S &format,
+         basic_format_args<typename basic_printf_context_t<
+           internal::basic_buffer<Char>>::type> args) {
+  basic_memory_buffer<Char> buffer;
+  printf(buffer, to_string_view(format), args);
+  return to_string(buffer);
+}
+
+/**
+  \rst
+  Formats arguments and returns the result as a string.
+
+  **Example**::
+
+    std::string message = fmt::sprintf("The answer is %d", 42);
+  \endrst
+*/
+template <typename S, typename... Args>
+inline FMT_ENABLE_IF_T(
+    internal::is_string<S>::value, std::basic_string<FMT_CHAR(S)>)
+    sprintf(const S &format, const Args & ... args) {
+  internal::check_format_string<Args...>(format);
+  typedef internal::basic_buffer<FMT_CHAR(S)> buffer;
+  typedef typename basic_printf_context_t<buffer>::type context;
+  format_arg_store<context, Args...> as{ args... };
+  return vsprintf(to_string_view(format),
+                  basic_format_args<context>(as));
+}
+
+template <typename S, typename Char = FMT_CHAR(S)>
+inline int vfprintf(std::FILE *f, const S &format,
+                    basic_format_args<typename basic_printf_context_t<
+                      internal::basic_buffer<Char>>::type> args) {
+  basic_memory_buffer<Char> buffer;
+  printf(buffer, to_string_view(format), args);
+  std::size_t size = buffer.size();
+  return std::fwrite(
+    buffer.data(), sizeof(Char), size, f) < size ? -1 : static_cast<int>(size);
+}
+
+/**
+  \rst
+  Prints formatted data to the file *f*.
+
+  **Example**::
+
+    fmt::fprintf(stderr, "Don't %s!", "panic");
+  \endrst
+ */
+template <typename S, typename... Args>
+inline FMT_ENABLE_IF_T(internal::is_string<S>::value, int)
+    fprintf(std::FILE *f, const S &format, const Args & ... args) {
+  internal::check_format_string<Args...>(format);
+  typedef internal::basic_buffer<FMT_CHAR(S)> buffer;
+  typedef typename basic_printf_context_t<buffer>::type context;
+  format_arg_store<context, Args...> as{ args... };
+  return vfprintf(f, to_string_view(format),
+                  basic_format_args<context>(as));
+}
+
+template <typename S, typename Char = FMT_CHAR(S)>
+inline int vprintf(const S &format,
+                   basic_format_args<typename basic_printf_context_t<
+                    internal::basic_buffer<Char>>::type> args) {
+  return vfprintf(stdout, to_string_view(format), args);
+}
+
+/**
+  \rst
+  Prints formatted data to ``stdout``.
+
+  **Example**::
+
+    fmt::printf("Elapsed time: %.2f seconds", 1.23);
+  \endrst
+ */
+template <typename S, typename... Args>
+inline FMT_ENABLE_IF_T(internal::is_string<S>::value, int)
+    printf(const S &format_str, const Args & ... args) {
+  internal::check_format_string<Args...>(format_str);
+  typedef internal::basic_buffer<FMT_CHAR(S)> buffer;
+  typedef typename basic_printf_context_t<buffer>::type context;
+  format_arg_store<context, Args...> as{ args... };
+  return vprintf(to_string_view(format_str),
+                 basic_format_args<context>(as));
+}
+
+template <typename S, typename Char = FMT_CHAR(S)>
+inline int vfprintf(std::basic_ostream<Char> &os,
+                    const S &format,
+                    basic_format_args<typename basic_printf_context_t<
+                      internal::basic_buffer<Char>>::type> args) {
+  basic_memory_buffer<Char> buffer;
+  printf(buffer, to_string_view(format), args);
+  internal::write(os, buffer);
+  return static_cast<int>(buffer.size());
+}
+
+/**
+  \rst
+  Prints formatted data to the stream *os*.
+
+  **Example**::
+
+    fmt::fprintf(cerr, "Don't %s!", "panic");
+  \endrst
+ */
+template <typename S, typename... Args>
+inline FMT_ENABLE_IF_T(internal::is_string<S>::value, int)
+    fprintf(std::basic_ostream<FMT_CHAR(S)> &os,
+            const S &format_str, const Args & ... args) {
+  internal::check_format_string<Args...>(format_str);
+  typedef internal::basic_buffer<FMT_CHAR(S)> buffer;
+  typedef typename basic_printf_context_t<buffer>::type context;
+  format_arg_store<context, Args...> as{ args... };
+  return vfprintf(os, to_string_view(format_str),
+                  basic_format_args<context>(as));
+}
+FMT_END_NAMESPACE
+
+#endif  // FMT_PRINTF_H_