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// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab ft=cpp
/*
* Ceph - scalable distributed file system
*
* Copyright (C) 2019 Red Hat, Inc.
*
* This is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2.1, as published by the Free Software
* Foundation. See file COPYING.
*
*/
#pragma once
#include <string_view>
namespace ceph {
// a forward iterator over the parts of a split string
class spliterator {
std::string_view str; // full string
std::string_view delims; // delimiters
using size_type = std::string_view::size_type;
size_type pos = 0; // start position of current part
std::string_view part; // view of current part
// return the next part after the given position
std::string_view next(size_type end) {
pos = str.find_first_not_of(delims, end);
if (pos == str.npos) {
return {};
}
return str.substr(pos, str.find_first_of(delims, pos) - pos);
}
public:
// types required by std::iterator_traits
using difference_type = int;
using value_type = std::string_view;
using pointer = const value_type*;
using reference = const value_type&;
using iterator_category = std::forward_iterator_tag;
spliterator() = default;
spliterator(std::string_view str, std::string_view delims)
: str(str), delims(delims), pos(0), part(next(0))
{}
spliterator& operator++() {
part = next(pos + part.size());
return *this;
}
spliterator operator++(int) {
spliterator tmp = *this;
part = next(pos + part.size());
return tmp;
}
reference operator*() const { return part; }
pointer operator->() const { return ∂ }
friend bool operator==(const spliterator& lhs, const spliterator& rhs) {
return lhs.part.data() == rhs.part.data()
&& lhs.part.size() == rhs.part.size();
}
friend bool operator!=(const spliterator& lhs, const spliterator& rhs) {
return lhs.part.data() != rhs.part.data()
|| lhs.part.size() != rhs.part.size();
}
};
// represents an immutable range of split string parts
//
// ranged-for loop example:
//
// for (std::string_view s : split(input)) {
// ...
//
// container initialization example:
//
// auto parts = split(input);
//
// std::vector<std::string> strings;
// strings.assign(parts.begin(), parts.end());
//
class split {
std::string_view str; // full string
std::string_view delims; // delimiters
public:
split(std::string_view str, std::string_view delims = ";,= \t\n")
: str(str), delims(delims) {}
using iterator = spliterator;
using const_iterator = spliterator;
iterator begin() const { return {str, delims}; }
const_iterator cbegin() const { return {str, delims}; }
iterator end() const { return {}; }
const_iterator cend() const { return {}; }
};
} // namespace ceph
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