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/*
* Copyright 2015-2021 Max Kellermann <max.kellermann@gmail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef ALLOCATED_STRING_HXX
#define ALLOCATED_STRING_HXX
#include "StringPointer.hxx"
#include <algorithm>
#include <cstddef>
#include <string_view>
/**
* A string pointer whose memory is managed by this class.
*
* Unlike std::string, this object can hold a "nullptr" special value.
*/
template<typename T>
class BasicAllocatedString {
public:
using value_type = typename StringPointer<T>::value_type;
using reference = typename StringPointer<T>::reference;
using const_reference = typename StringPointer<T>::const_reference;
using pointer = typename StringPointer<T>::pointer;
using const_pointer = typename StringPointer<T>::const_pointer;
using string_view = std::basic_string_view<T>;
using size_type = std::size_t;
static constexpr value_type SENTINEL = '\0';
private:
pointer value = nullptr;
explicit BasicAllocatedString(pointer _value) noexcept
:value(_value) {}
public:
BasicAllocatedString() noexcept = default;
BasicAllocatedString(std::nullptr_t n) noexcept
:value(n) {}
BasicAllocatedString(BasicAllocatedString &&src) noexcept
:value(src.Steal()) {}
~BasicAllocatedString() noexcept {
delete[] value;
}
static BasicAllocatedString Donate(pointer value) noexcept {
return BasicAllocatedString(value);
}
static BasicAllocatedString Null() noexcept {
return nullptr;
}
static BasicAllocatedString Empty() {
auto p = new value_type[1];
p[0] = SENTINEL;
return Donate(p);
}
static BasicAllocatedString Duplicate(string_view src) {
auto p = new value_type[src.size() + 1];
*std::copy_n(src.data(), src.size(), p) = SENTINEL;
return Donate(p);
}
BasicAllocatedString &operator=(BasicAllocatedString &&src) noexcept {
std::swap(value, src.value);
return *this;
}
constexpr bool operator==(std::nullptr_t) const noexcept {
return value == nullptr;
}
constexpr bool operator!=(std::nullptr_t) const noexcept {
return value != nullptr;
}
constexpr bool IsNull() const noexcept {
return value == nullptr;
}
operator string_view() const noexcept {
return value;
}
constexpr const_pointer c_str() const noexcept {
return value;
}
bool empty() const noexcept {
return *value == SENTINEL;
}
constexpr pointer data() const noexcept {
return value;
}
reference operator[](size_type i) noexcept {
return value[i];
}
const reference operator[](size_type i) const noexcept {
return value[i];
}
pointer Steal() noexcept {
return std::exchange(value, nullptr);
}
BasicAllocatedString Clone() const {
return Duplicate(*this);
}
};
class AllocatedString : public BasicAllocatedString<char> {
public:
using BasicAllocatedString::BasicAllocatedString;
AllocatedString() noexcept = default;
AllocatedString(BasicAllocatedString<value_type> &&src) noexcept
:BasicAllocatedString(std::move(src)) {}
};
#endif
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