fmtlegacy/fmt/ostream.h

/*
 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 "fmt/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());
  }

  int_type overflow(int_type ch = traits_type::eof()) {
    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);

template <typename Char, typename T>
BasicStringRef<Char> format_value(
    internal::MemoryBuffer<Char, internal::INLINE_BUFFER_SIZE> &buffer,
    const T &value) {
  internal::FormatBuf<Char> format_buf(buffer);
  std::basic_ostream<Char> output(&format_buf);
  output << value;
  return BasicStringRef<Char>(&buffer[0], format_buf.size());
}
}  // namespace internal

// Formats a value.
template <typename Char, typename T>
void format_value(basic_writer<Char> &w, const T &value,
                  basic_format_context<Char> &ctx) {
  internal::MemoryBuffer<Char, internal::INLINE_BUFFER_SIZE> buffer;
  auto str = internal::format_value(buffer, value);
  do_format_arg< ArgFormatter<Char> >(
        w, internal::make_arg< basic_format_context<Char> >(str), ctx);
}

FMT_API void vprint(std::ostream &os, CStringRef format_str, format_args args);

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

  **Example**::

    print(cerr, "Don't {}!", "panic");
  \endrst
 */
template <typename... Args>
inline void print(std::ostream &os, CStringRef format_str,
                  const Args & ... args) {
  vprint(os, format_str, make_format_args(args...));
}
}  // namespace fmt

#ifdef FMT_HEADER_ONLY
# include "ostream.cc"
#endif

#endif  // FMT_OSTREAM_H_