Atmosphere/libraries/libvapours/include/vapours/util/util_string_view.hpp
2021-01-20 23:39:31 -08:00

348 lines
16 KiB
C++

/*
* Copyright (c) 2018-2020 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <vapours/common.hpp>
#include <vapours/assert.hpp>
namespace ams::util {
template<class _CharT, class _Traits = std::char_traits<_CharT>>
class basic_string_view {
static_assert(!std::is_array<_CharT>::value);
static_assert(std::is_trivial<_CharT>::value && std::is_standard_layout<_CharT>::value);
static_assert(std::same_as<_CharT, typename _Traits::char_type>);
public:
using traits_type = _Traits;
using value_type = _CharT;
using pointer = value_type *;
using const_pointer = const value_type *;
using reference = value_type &;
using const_reference = const value_type &;
using const_iterator = const value_type *;
using iterator = const_iterator;
using const_reverse_iterator = std::reverse_iterator<const_iterator>;
using reverse_iterator = const_reverse_iterator;
using size_type = size_t;
using difference_type = ptrdiff_t;
static constexpr size_type npos = size_type(-1);
private:
static constexpr int _s_compare(size_type lhs, size_type rhs) noexcept {
const difference_type diff = lhs - rhs;
if (diff > std::numeric_limits<int>::max()) {
return std::numeric_limits<int>::max();
}
if (diff < std::numeric_limits<int>::min()) {
return std::numeric_limits<int>::min();
}
return static_cast<int>(diff);
}
private:
const_pointer m_str;
size_type m_len;
public:
constexpr basic_string_view() noexcept : m_str(nullptr), m_len(0) { /* ... */ }
constexpr basic_string_view(const _CharT *str, size_type len) noexcept : m_str(str), m_len(len) { /* ... */ }
constexpr basic_string_view(const _CharT *str) noexcept : m_str(str), m_len(str ? traits_type::length(str) : 0) { /* ... */ }
template<std::contiguous_iterator _It, std::sized_sentinel_for<_It> _End> requires std::same_as<std::iter_value_t<_It>, _CharT> && (!std::convertible_to<_End, size_type>)
constexpr basic_string_view(_It first, _End last) noexcept : m_str(std::to_address(first)), m_len(last - first) { /* ... */ }
constexpr basic_string_view(const basic_string_view &) noexcept = default;
constexpr basic_string_view &operator=(const basic_string_view &) noexcept = default;
constexpr const_iterator begin() const noexcept { return m_str; }
constexpr const_iterator end() const noexcept { return m_str + m_len; }
constexpr const_iterator cbegin() const noexcept { return m_str; }
constexpr const_iterator cend() const noexcept { return m_str + m_len; }
constexpr const_reverse_iterator rbegin() const noexcept { return const_reverse_iterator(this->end()); }
constexpr const_reverse_iterator rend() const noexcept { return const_reverse_iterator(this->begin()); }
constexpr const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator(this->cend()); }
constexpr const_reverse_iterator crend() const noexcept { return const_reverse_iterator(this->cbegin()); }
constexpr size_type size() const noexcept { return m_len; }
constexpr size_type length() const noexcept { return m_len; }
constexpr size_type max_size() const noexcept { return (npos - sizeof(size_type) - sizeof(void *)) / sizeof(value_type) / 4; }
[[nodiscard]] constexpr bool empty() const noexcept { return m_len == 0; }
constexpr const_reference operator[](size_type pos) const noexcept {
AMS_ASSERT(pos < m_len);
return *(m_str + pos);
}
constexpr const_reference at(size_type pos) const noexcept {
AMS_ASSERT(pos < m_len);
AMS_ABORT_UNLESS(pos < m_len);
return *(m_str + pos);
}
constexpr const_reference front() const noexcept {
AMS_ASSERT(m_len > 0);
return *m_str;
}
constexpr const_reference back() const noexcept {
AMS_ASSERT(m_len > 0);
return *(m_str + m_len - 1);
}
constexpr const_pointer data() const noexcept { return m_str; }
constexpr void remove_prefix(size_type n) noexcept {
AMS_ASSERT(m_len >= n);
m_str += n;
m_len -= n;
}
constexpr void remove_suffix(size_type n) noexcept {
AMS_ASSERT(m_len >= n);
m_len -= n;
}
constexpr void swap(basic_string_view &rhs) noexcept {
auto tmp = *this;
*this = rhs;
rhs = tmp;
}
constexpr size_type copy(_CharT *str, size_type n, size_type pos = 0) const noexcept {
AMS_ASSERT(pos <= this->size());
const size_type rlen = std::min(n, m_len - pos);
traits_type::copy(str, this->data() + pos, rlen);
return rlen;
}
constexpr basic_string_view substr(size_type pos = 0, size_type n = npos) const noexcept {
AMS_ASSERT(pos <= this->size());
const size_type rlen = std::min(n, m_len - pos);
return basic_string_view{m_str + pos, rlen};
}
constexpr int compare(basic_string_view str) const noexcept {
const size_type rlen = std::min(m_len, str.m_len);
int ret = traits_type::compare(m_str, str.m_str, rlen);
if (ret == 0) {
ret = _s_compare(m_len, str.m_len);
}
return ret;
}
constexpr int compare(size_type pos, size_type n, basic_string_view str) const noexcept {
return this->substr(pos, n).compare(str);
}
constexpr int compare(size_type pos1, size_type n1, basic_string_view str, size_type pos2, size_type n2) const {
return this->substr(pos1, n1).compare(str.substr(pos2, n2));
}
constexpr int compare(const _CharT *str) const noexcept {
return this->compare(basic_string_view(str));
}
constexpr int compare(size_type pos, size_type n, const _CharT *str) const noexcept {
return this->substr(pos, n).compare(basic_string_view(str));
}
constexpr int compare(size_type pos, size_type n, const _CharT *str, size_type n2) const noexcept {
return this->substr(pos, n).compare(basic_string_view(str, n2));
}
constexpr bool starts_with(basic_string_view x) const noexcept { return this->substr(0, x.size()) == x; }
constexpr bool starts_with(_CharT x) const noexcept { return !this->empty() && traits_type::eq(this->front(), x); }
constexpr bool starts_with(const _CharT *x) const noexcept { return this->starts_with(basic_string_view(x)); }
constexpr bool ends_with(basic_string_view x) const noexcept { return this->size() >= x.size() && this->compare(this->size() - x.size(), npos, x) == 0; }
constexpr bool ends_with(_CharT x) const noexcept { return !this->empty() && traits_type::eq(this->back(), x); }
constexpr bool ends_with(const _CharT *x) const noexcept { return this->ends_with(basic_string_view(x)); }
constexpr size_type find(const _CharT *str, size_type pos, size_type n) const noexcept {
if (n == 0) {
return pos + m_len ? pos : npos;
}
if (n <= m_len) {
for (/* ... */; pos <= m_len - n; ++pos) {
if (traits_type::eq(m_str[pos], str[0]) && traits_type::compare(m_str + pos + 1, str + 1, n - 1) == 0) {
return pos;
}
}
}
return npos;
}
constexpr size_type find(_CharT c, size_type pos = 0) const noexcept {
size_type ret = npos;
if (pos < m_len) {
const size_type n = m_len - pos;
if (const _CharT *p = traits_type::find(m_str + pos, n, c); p) {
ret = p - m_str;
}
}
return ret;
}
constexpr size_type find(basic_string_view str, size_type pos = 0) const noexcept { return this->find(str.m_str, pos, str.m_len); }
__attribute__((nonnull(1)))
constexpr size_type find(const _CharT *str, size_type pos = 0) const noexcept { return this->find(str, pos, traits_type::length(str)); }
constexpr size_type rfind(const _CharT *str, size_type pos, size_type n) const noexcept {
if (n <= m_len) {
pos = std::min(size_type(m_len - n), pos);
do {
if (traits_type::compare(m_str + pos, str, n) == 0) {
return pos;
}
} while (pos-- > 0);
}
return npos;
}
constexpr size_type rfind(_CharT c, size_type pos = 0) const noexcept {
size_type size = m_len;
if (size > 0) {
if (--size > pos) {
size = pos;
}
for (++size; size-- > 0; /* ... */) {
if (traits_type::eq(m_str[size], c)) {
return size;
}
}
}
return npos;
}
constexpr size_type rfind(basic_string_view str, size_type pos = 0) const noexcept { return this->rfind(str.m_str, pos, str.m_len); }
__attribute__((nonnull(1)))
constexpr size_type rfind(const _CharT *str, size_type pos = 0) const noexcept { return this->rfind(str, pos, traits_type::length(str)); }
constexpr size_type find_first_of(const _CharT *str, size_type pos, size_t n) const noexcept {
for (/* ... */; n && pos < m_len; ++pos) {
if (const _CharT *p = traits_type::find(str, n, m_str[pos]); p) {
return pos;
}
}
return npos;
}
constexpr size_type find_first_of(basic_string_view str, size_type pos = 0) const noexcept { return this->find_first_of(str.m_str, pos, str.m_len); }
constexpr size_type find_first_of(_CharT c, size_type pos = 0) const noexcept { return this->find(c, pos); }
__attribute__((nonnull(1)))
constexpr size_type find_first_of(const _CharT *str, size_type pos = 0) const noexcept { return this->find_first_of(str, pos, traits_type::length(str)); }
constexpr size_type find_last_of(const _CharT *str, size_type pos, size_t n) const noexcept {
size_type size = this->size();
if (size && n) {
if (--size > pos) {
size = pos;
}
do {
if (traits_type::find(str, n, m_str[size])) {
return size;
}
} while (size-- != 0);
}
return npos;
}
constexpr size_type find_last_of(basic_string_view str, size_type pos = 0) const noexcept { return this->find_last_of(str.m_str, pos, str.m_len); }
constexpr size_type find_last_of(_CharT c, size_type pos = 0) const noexcept { return this->rfind(c, pos); }
__attribute__((nonnull(1)))
constexpr size_type find_last_of(const _CharT *str, size_type pos = 0) const noexcept { return this->find_first_of(str, pos, traits_type::length(str)); }
constexpr size_type find_first_not_of(const _CharT *str, size_type pos, size_t n) const noexcept {
for (/* ... */; pos < m_len; ++pos) {
if (!traits_type::find(str, n, m_str[pos])) {
return pos;
}
}
return npos;
}
constexpr size_type find_first_not_of(_CharT c, size_type pos = 0) const noexcept {
for (/* ... */; pos < m_len; ++pos) {
if (!traits_type::eq(m_str[pos], c)) {
return pos;
}
}
return npos;
}
constexpr size_type find_first_not_of(basic_string_view str, size_type pos = 0) const noexcept { return this->find_first_not_of(str.m_str, pos, str.m_len); }
__attribute__((nonnull(1)))
constexpr size_type find_first_not_of(const _CharT *str, size_type pos = 0) const noexcept { return this->find_first_not_of(str, pos, traits_type::length(str)); }
constexpr size_type find_last_not_of(const _CharT *str, size_type pos, size_t n) const noexcept {
size_type size = this->size();
if (size) {
if (--size > pos) {
size = pos;
}
do {
if (!traits_type::find(str, n, m_str[size])) {
return size;
}
} while (size-- != 0);
}
return npos;
}
constexpr size_type find_last_not_of(_CharT c, size_type pos = 0) const noexcept {
size_type size = this->size();
if (size) {
if (--size > pos) {
size = pos;
}
do {
if (!traits_type::eq(m_str[size], c)) {
return size;
}
} while (size-- != 0);
}
return npos;
}
constexpr size_type find_last_not_of(basic_string_view str, size_type pos = 0) const noexcept { return this->find_last_not_of(str.m_str, pos, str.m_len); }
__attribute__((nonnull(1)))
constexpr size_type find_last_not_of(const _CharT *str, size_type pos = 0) const noexcept { return this->find_last_not_of(str, pos, traits_type::length(str)); }
constexpr friend bool operator==(const basic_string_view &lhs, const basic_string_view &rhs) noexcept { return lhs.compare(rhs) == 0; }
constexpr friend bool operator!=(const basic_string_view &lhs, const basic_string_view &rhs) noexcept { return lhs.compare(rhs) != 0; }
constexpr friend bool operator<=(const basic_string_view &lhs, const basic_string_view &rhs) noexcept { return lhs.compare(rhs) <= 0; }
constexpr friend bool operator>=(const basic_string_view &lhs, const basic_string_view &rhs) noexcept { return lhs.compare(rhs) >= 0; }
constexpr friend bool operator< (const basic_string_view &lhs, const basic_string_view &rhs) noexcept { return lhs.compare(rhs) < 0; }
constexpr friend bool operator> (const basic_string_view &lhs, const basic_string_view &rhs) noexcept { return lhs.compare(rhs) > 0; }
};
template<std::contiguous_iterator _It, std::sized_sentinel_for<_It> _End>
basic_string_view(_It, _End) -> basic_string_view<std::iter_value_t<_It>>;
using string_view = basic_string_view<char>;
}