1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
|
// Formatting library for C++ - std::ostream support
//
// Copyright (c) 2012 - present, Victor Zverovich
// All rights reserved.
//
// For the license information refer to format.h.
#ifndef FMT_OSTREAM_H_
#define FMT_OSTREAM_H_
#include <ostream>
#include "format.h"
FMT_BEGIN_NAMESPACE
namespace internal {
template <class Char> class formatbuf : public std::basic_streambuf<Char> {
private:
using int_type = typename std::basic_streambuf<Char>::int_type;
using traits_type = typename std::basic_streambuf<Char>::traits_type;
buffer<Char>& buffer_;
public:
formatbuf(buffer<Char>& buf) : buffer_(buf) {}
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;
}
};
template <typename Char> struct test_stream : std::basic_ostream<Char> {
private:
// Hide all operator<< from std::basic_ostream<Char>.
void_t<> operator<<(null<>);
void_t<> operator<<(const Char*);
template <typename T, FMT_ENABLE_IF(std::is_convertible<T, int>::value &&
!std::is_enum<T>::value)>
void_t<> operator<<(T);
};
// Checks if T has a user-defined operator<< (e.g. not a member of
// std::ostream).
template <typename T, typename Char> class is_streamable {
private:
template <typename U>
static bool_constant<!std::is_same<decltype(std::declval<test_stream<Char>&>()
<< std::declval<U>()),
void_t<>>::value>
test(int);
template <typename> static std::false_type test(...);
using result = decltype(test<T>(0));
public:
static const bool value = result::value;
};
// Write the content of buf to os.
template <typename Char>
void write(std::basic_ostream<Char>& os, buffer<Char>& buf) {
const Char* buf_data = buf.data();
using unsigned_streamsize = std::make_unsigned<std::streamsize>::type;
unsigned_streamsize size = buf.size();
unsigned_streamsize max_size = to_unsigned(max_value<std::streamsize>());
do {
unsigned_streamsize n = size <= max_size ? size : max_size;
os.write(buf_data, static_cast<std::streamsize>(n));
buf_data += n;
size -= n;
} while (size != 0);
}
template <typename Char, typename T>
void format_value(buffer<Char>& buf, const T& value,
locale_ref loc = locale_ref()) {
formatbuf<Char> format_buf(buf);
std::basic_ostream<Char> output(&format_buf);
if (loc) output.imbue(loc.get<std::locale>());
output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
output << value;
buf.resize(buf.size());
}
// Formats an object of type T that has an overloaded ostream operator<<.
template <typename T, typename Char>
struct fallback_formatter<T, Char, enable_if_t<is_streamable<T, Char>::value>>
: formatter<basic_string_view<Char>, Char> {
template <typename Context>
auto format(const T& value, Context& ctx) -> decltype(ctx.out()) {
basic_memory_buffer<Char> buffer;
format_value(buffer, value, ctx.locale());
basic_string_view<Char> str(buffer.data(), buffer.size());
return formatter<basic_string_view<Char>, Char>::format(str, ctx);
}
};
} // namespace internal
template <typename Char>
void vprint(std::basic_ostream<Char>& os, basic_string_view<Char> format_str,
basic_format_args<buffer_context<Char>> args) {
basic_memory_buffer<Char> buffer;
internal::vformat_to(buffer, format_str, args);
internal::write(os, buffer);
}
/**
\rst
Prints formatted data to the stream *os*.
**Example**::
fmt::print(cerr, "Don't {}!", "panic");
\endrst
*/
template <typename S, typename... Args,
typename Char = enable_if_t<internal::is_string<S>::value, char_t<S>>>
void print(std::basic_ostream<Char>& os, const S& format_str, Args&&... args) {
vprint(os, to_string_view(format_str),
{internal::make_args_checked<Args...>(format_str, args...)});
}
FMT_END_NAMESPACE
#endif // FMT_OSTREAM_H_
|
