explorer/ext/fmt/ostream.h
2017-03-13 16:35:45 +08:00

149 lines
3.7 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_;
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_