You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
132 lines
3.2 KiB
132 lines
3.2 KiB
/*
|
|
* Copyright (c) 2016-present, Facebook, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This source code is licensed under both the BSD-style license (found in the
|
|
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
|
|
* in the COPYING file in the root directory of this source tree).
|
|
*/
|
|
|
|
/**
|
|
* A subset of `folly/Range.h`.
|
|
* All code copied verbatim modulo formatting
|
|
*/
|
|
#pragma once
|
|
|
|
#include "utils/Likely.h"
|
|
|
|
#include <cstddef>
|
|
#include <cstring>
|
|
#include <stdexcept>
|
|
#include <string>
|
|
#include <type_traits>
|
|
|
|
namespace pzstd {
|
|
|
|
namespace detail {
|
|
/*
|
|
*Use IsCharPointer<T>::type to enable const char* or char*.
|
|
*Use IsCharPointer<T>::const_type to enable only const char*.
|
|
*/
|
|
template <class T>
|
|
struct IsCharPointer {};
|
|
|
|
template <>
|
|
struct IsCharPointer<char*> {
|
|
typedef int type;
|
|
};
|
|
|
|
template <>
|
|
struct IsCharPointer<const char*> {
|
|
typedef int const_type;
|
|
typedef int type;
|
|
};
|
|
|
|
} // namespace detail
|
|
|
|
template <typename Iter>
|
|
class Range {
|
|
Iter b_;
|
|
Iter e_;
|
|
|
|
public:
|
|
using size_type = std::size_t;
|
|
using iterator = Iter;
|
|
using const_iterator = Iter;
|
|
using value_type = typename std::remove_reference<
|
|
typename std::iterator_traits<Iter>::reference>::type;
|
|
using reference = typename std::iterator_traits<Iter>::reference;
|
|
|
|
constexpr Range() : b_(), e_() {}
|
|
constexpr Range(Iter begin, Iter end) : b_(begin), e_(end) {}
|
|
|
|
constexpr Range(Iter begin, size_type size) : b_(begin), e_(begin + size) {}
|
|
|
|
template <class T = Iter, typename detail::IsCharPointer<T>::type = 0>
|
|
/* implicit */ Range(Iter str) : b_(str), e_(str + std::strlen(str)) {}
|
|
|
|
template <class T = Iter, typename detail::IsCharPointer<T>::const_type = 0>
|
|
/* implicit */ Range(const std::string& str)
|
|
: b_(str.data()), e_(b_ + str.size()) {}
|
|
|
|
// Allow implicit conversion from Range<From> to Range<To> if From is
|
|
// implicitly convertible to To.
|
|
template <
|
|
class OtherIter,
|
|
typename std::enable_if<
|
|
(!std::is_same<Iter, OtherIter>::value &&
|
|
std::is_convertible<OtherIter, Iter>::value),
|
|
int>::type = 0>
|
|
constexpr /* implicit */ Range(const Range<OtherIter>& other)
|
|
: b_(other.begin()), e_(other.end()) {}
|
|
|
|
Range(const Range&) = default;
|
|
Range(Range&&) = default;
|
|
|
|
Range& operator=(const Range&) & = default;
|
|
Range& operator=(Range&&) & = default;
|
|
|
|
constexpr size_type size() const {
|
|
return e_ - b_;
|
|
}
|
|
bool empty() const {
|
|
return b_ == e_;
|
|
}
|
|
Iter data() const {
|
|
return b_;
|
|
}
|
|
Iter begin() const {
|
|
return b_;
|
|
}
|
|
Iter end() const {
|
|
return e_;
|
|
}
|
|
|
|
void advance(size_type n) {
|
|
if (UNLIKELY(n > size())) {
|
|
throw std::out_of_range("index out of range");
|
|
}
|
|
b_ += n;
|
|
}
|
|
|
|
void subtract(size_type n) {
|
|
if (UNLIKELY(n > size())) {
|
|
throw std::out_of_range("index out of range");
|
|
}
|
|
e_ -= n;
|
|
}
|
|
|
|
Range subpiece(size_type first, size_type length = std::string::npos) const {
|
|
if (UNLIKELY(first > size())) {
|
|
throw std::out_of_range("index out of range");
|
|
}
|
|
|
|
return Range(b_ + first, std::min(length, size() - first));
|
|
}
|
|
};
|
|
|
|
using ByteRange = Range<const unsigned char*>;
|
|
using MutableByteRange = Range<unsigned char*>;
|
|
using StringPiece = Range<const char*>;
|
|
}
|