1 + 
//
 
2 + 
// Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com)
 
3 + 
//
 
4 + 
// Distributed under the Boost Software License, Version 1.0. (See accompanying
 
5 + 
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
6 + 
//
 
7 + 
// Official repository: https://github.com/boostorg/url
 
8 + 
//
 
9 +
 
10 + 
#ifndef BOOST_URL_DETAIL_MOVE_CHARS_HPP
 
11 + 
#define BOOST_URL_DETAIL_MOVE_CHARS_HPP
 
12 +
 
13 + 
#include <boost/core/detail/string_view.hpp>
 
14 + 
#include <boost/assert.hpp>
 
15 + 
#include <cstring>
 
16 + 
#include <functional>
 
17 +
 
18 + 
namespace boost {
 
19 + 
namespace urls {
 
20 + 
namespace detail {
 
21 +
 
22 + 
// Moves characters, and adjusts any passed
 
23 + 
// views if they point to any moved characters.
 
24 +
 
25 + 
// true if s completely overlapped by buf
 
26 + 
inline
 
27 + 
bool
 
28 + 
is_overlapping(
 
29 + 
    core::string_view buf,
 
30 + 
    core::string_view s) noexcept
 
31 + 
{
 
32 + 
    auto const b0 = buf.data();
 
33 + 
    auto const e0 = b0 + buf.size();
 
34 + 
    auto const b1 = s.data();
 
35 + 
    auto const e1 = b1 + s.size();
 
36 + 
    auto const less_equal =
 
37 + 
        std::less_equal<char const*>();
 
38 + 
    if(less_equal(e0, b1))
 
39 + 
        return false;
 
40 + 
    if(less_equal(e1, b0))
 
41 + 
        return false;
 
42 + 
    // partial overlap is undefined
 
43 + 
    BOOST_ASSERT(less_equal(e1, e0));
 
44 + 
    BOOST_ASSERT(less_equal(b0, b1));
 
45 + 
    return true;
 
46 + 
}
 
47 +
 
48 + 
inline
 
49 + 
void
 
50 + 
move_chars_impl(
 
51 + 
    std::ptrdiff_t,
 
52 + 
    core::string_view const&) noexcept
 
53 + 
{
 
54 + 
}
 
55 +
 
56 + 
template<class... Sn>
 
57 + 
void
 
58 + 
move_chars_impl(
 
59 + 
    std::ptrdiff_t d,
 
60 + 
    core::string_view const& buf,
 
61 + 
    core::string_view& s,
 
62 + 
    Sn&... sn) noexcept
 
63 + 
{
 
64 + 
    if(is_overlapping(buf, s))
 
65 + 
        s = {s.data() + d, s.size()};
 
66 + 
    move_chars_impl(d, buf, sn...);
 
67 + 
}
 
68 +
 
69 + 
template<class... Args>
 
70 + 
void
 
71 + 
move_chars(
 
72 + 
    char* dest,
 
73 + 
    char const* src,
 
74 + 
    std::size_t n,
 
75 + 
    Args&... args) noexcept
 
76 + 
{
 
77 + 
    move_chars_impl(
 
78 + 
        dest - src,
 
79 + 
        core::string_view(src, n),
 
80 + 
        args...);
 
81 + 
    std::memmove(
 
82 + 
        dest, src, n);
 
83 + 
}
 
84 +
 
85 + 
} // detail
 
86 + 
} // urls
 
87 + 
} // boost
 
88 +
 
89 + 
#endif