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
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
|
// -*- C++ -*-
// Boost general library 'format' ---------------------------
// See http://www.boost.org for updates, documentation, and revision history.
// (C) Samuel Krempp 2001
// krempp@crans.ens-cachan.fr
// Permission to copy, use, modify, sell and
// distribute this software is granted provided this copyright notice appears
// in all copies. This software is provided "as is" without express or implied
// warranty, and with no claim as to its suitability for any purpose.
// ideas taken from R�diger Loos's format class
// and Karl Nelson's ofstream
// ----------------------------------------------------------------------------
// internals.hpp : internal structs. included by format.hpp
// stream_format_state, and format_item
// ----------------------------------------------------------------------------
#ifndef BOOST_FORMAT_INTERNALS_HPP
#define BOOST_FORMAT_INTERNALS_HPP
#include <string>
#include <sstream>
namespace boost {
namespace io {
namespace detail {
// --------------
// set of params that define the format state of a stream
struct stream_format_state
{
typedef std::ios basic_ios;
std::streamsize width_;
std::streamsize precision_;
char fill_;
std::ios::fmtflags flags_;
stream_format_state() : width_(-1), precision_(-1), fill_(0), flags_(std::ios::dec) {}
stream_format_state(basic_ios& os) {set_by_stream(os); }
void apply_on(basic_ios & os) const; //- applies format_state to the stream
template<class T> void apply_manip(T manipulator) //- modifies state by applying manipulator.
{ apply_manip_body<T>( *this, manipulator) ; }
void reset(); //- sets to default state.
void set_by_stream(const basic_ios& os); //- sets to os's state.
};
// --------------
// format_item : stores all parameters that can be defined by directives in the format-string
struct format_item
{
enum pad_values { zeropad = 1, spacepad =2, centered=4, tabulation = 8 };
enum arg_values { argN_no_posit = -1, // non-positional directive. argN will be set later.
argN_tabulation = -2, // tabulation directive. (no argument read)
argN_ignored = -3 // ignored directive. (no argument read)
};
typedef BOOST_IO_STD ios basic_ios;
typedef detail::stream_format_state stream_format_state;
typedef std::string string_t;
typedef BOOST_IO_STD ostringstream internal_stream_t;
int argN_; //- argument number (starts at 0, eg : %1 => argN=0)
// negative values are used for items that don't process
// an argument
string_t res_; //- result of the formatting of this item
string_t appendix_; //- piece of string between this item and the next
stream_format_state ref_state_;// set by parsing the format_string, is only affected by modify_item
stream_format_state state_; // always same as ref_state, _unless_ modified by manipulators 'group(..)'
// non-stream format-state parameters
signed int truncate_; //- is >=0 for directives like %.5s (take 5 chars from the string)
unsigned int pad_scheme_; //- several possible padding schemes can mix. see pad_values
format_item() : argN_(argN_no_posit), truncate_(-1), pad_scheme_(0) {}
void compute_states(); // sets states according to truncate and pad_scheme.
};
// -----------------------------------------------------------
// Definitions
// -----------------------------------------------------------
// --- stream_format_state:: -------------------------------------------
inline
void stream_format_state::apply_on(basic_ios & os) const
// set the state of this stream according to our params
{
if(width_ != -1)
os.width(width_);
if(precision_ != -1)
os.precision(precision_);
if(fill_ != 0)
os.fill(fill_);
os.flags(flags_);
}
inline
void stream_format_state::set_by_stream(const basic_ios& os)
// set our params according to the state of this stream
{
flags_ = os.flags();
width_ = os.width();
precision_ = os.precision();
fill_ = os.fill();
}
template<class T> inline
void apply_manip_body( stream_format_state& self,
T manipulator)
// modify our params according to the manipulator
{
BOOST_IO_STD stringstream ss;
self.apply_on( ss );
ss << manipulator;
self.set_by_stream( ss );
}
inline
void stream_format_state::reset()
// set our params to standard's default state
{
width_=-1; precision_=-1; fill_=0;
flags_ = std::ios::dec;
}
// --- format_items:: -------------------------------------------
inline
void format_item::compute_states()
// reflect pad_scheme_ on state_ and ref_state_
// because some pad_schemes has complex consequences on several state params.
{
if(pad_scheme_ & zeropad)
{
if(ref_state_.flags_ & std::ios::left)
{
pad_scheme_ = pad_scheme_ & (~zeropad); // ignore zeropad in left alignment
}
else
{
ref_state_.fill_='0';
ref_state_.flags_ |= std::ios::internal;
}
}
state_ = ref_state_;
}
} } } // namespaces boost :: io :: detail
#endif // BOOST_FORMAT_INTERNALS_HPP
|