convert.hpp
3.5 KB
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
//
// Copyright (c) 2012 Artyom Beilis (Tonkikh)
// Copyright (c) 2020 Alexander Grund
//
// Distributed under the Boost Software License, Version 1.0.
// https://www.boost.org/LICENSE_1_0.txt
#ifndef BOOST_NOWIDE_UTF_CONVERT_HPP_INCLUDED
#define BOOST_NOWIDE_UTF_CONVERT_HPP_INCLUDED
#include <boost/nowide/detail/is_string_container.hpp>
#include <boost/nowide/replacement.hpp>
#include <boost/nowide/utf/utf.hpp>
#include <iterator>
#include <string>
namespace boost {
namespace nowide {
namespace utf {
/// Return the length of the given string in code units.
/// That is the number of elements of type Char until the first NULL character.
/// Equivalent to `std::strlen(s)` but can handle wide-strings
template<typename Char>
size_t strlen(const Char* s)
{
const Char* end = s;
while(*end)
end++;
return end - s;
}
/// Convert a buffer of UTF sequences in the range [source_begin, source_end)
/// from \a CharIn to \a CharOut to the output \a buffer of size \a buffer_size.
///
/// \return original buffer containing the NULL terminated string or NULL
///
/// If there is not enough room in the buffer NULL is returned, and the content of the buffer is undefined.
/// Any illegal sequences are replaced with the replacement character, see #BOOST_NOWIDE_REPLACEMENT_CHARACTER
template<typename CharOut, typename CharIn>
CharOut*
convert_buffer(CharOut* buffer, size_t buffer_size, const CharIn* source_begin, const CharIn* source_end)
{
CharOut* rv = buffer;
if(buffer_size == 0)
return nullptr;
buffer_size--;
while(source_begin != source_end)
{
code_point c = utf_traits<CharIn>::decode(source_begin, source_end);
if(c == illegal || c == incomplete)
{
c = BOOST_NOWIDE_REPLACEMENT_CHARACTER;
}
size_t width = utf_traits<CharOut>::width(c);
if(buffer_size < width)
{
rv = nullptr;
break;
}
buffer = utf_traits<CharOut>::encode(c, buffer);
buffer_size -= width;
}
*buffer++ = 0;
return rv;
}
/// Convert the UTF sequences in range [begin, end) from \a CharIn to \a CharOut
/// and return it as a string
///
/// Any illegal sequences are replaced with the replacement character, see #BOOST_NOWIDE_REPLACEMENT_CHARACTER
/// \tparam CharOut Output character type
template<typename CharOut, typename CharIn>
std::basic_string<CharOut> convert_string(const CharIn* begin, const CharIn* end)
{
std::basic_string<CharOut> result;
result.reserve(end - begin);
using inserter_type = std::back_insert_iterator<std::basic_string<CharOut>>;
inserter_type inserter(result);
code_point c;
while(begin != end)
{
c = utf_traits<CharIn>::decode(begin, end);
if(c == illegal || c == incomplete)
{
c = BOOST_NOWIDE_REPLACEMENT_CHARACTER;
}
utf_traits<CharOut>::encode(c, inserter);
}
return result;
}
} // namespace utf
} // namespace nowide
} // namespace boost
#endif