fmtlegacy/fmt/ostream.h
2017-10-14 07:38:16 -07:00

109 lines
2.9 KiB
C++

/*
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_;
public:
FormatBuf(Buffer<Char> &buffer) : buffer_(buffer) {}
protected:
// The put-area is actually always empty. This makes the implementation
// simpler and has the advantage that the streambuf and the buffer are always
// in sync and sputc never writes into uninitialized memory. The obvious
// disadvantage is that each call to sputc always results in a (virtual) call
// to overflow. There is no disadvantage here for sputn since this always
// results in a call to xsputn.
int_type overflow(int_type ch = traits_type::eof()) FMT_OVERRIDE {
if (!traits_type::eq_int_type(ch, traits_type::eof()))
buffer_.push_back(static_cast<Char>(ch));
return ch;
}
std::streamsize xsputn(const Char *s, std::streamsize count) FMT_OVERRIDE {
buffer_.append(s, s + count);
return count;
}
};
Yes &convert(std::ostream &);
struct DummyStream : std::ostream {
DummyStream(); // Suppress a bogus warning in MSVC.
// Hide all operator<< overloads from std::ostream.
template <typename T>
typename EnableIf<sizeof(T) == 0>::type operator<<(const T &);
};
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.
FMT_API void write(std::ostream &os, Writer &w);
} // 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.exceptions(std::ios_base::failbit | std::ios_base::badbit);
output << value;
BasicStringRef<Char> str(&buffer[0], buffer.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)
} // namespace fmt
#ifdef FMT_HEADER_ONLY
# include "ostream.cc"
#endif
#endif // FMT_OSTREAM_H_