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#pragma once
// iter.hpp - tools for dealing with iterators
//
// Copyright © 2012-2014 Ben Longbons <b.r.longbons@gmail.com>
//
// This file is part of The Mana World (Athena server)
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that 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/>.
#include "fwd.hpp"
#include <iterator>
namespace tmwa
{
/// Simple class to use a pair of iterators with foreach
template<class It>
class IteratorPair
{
It _b, _e;
public:
IteratorPair(It b, It e)
: _b(b), _e(e)
{}
It begin() { return _b; }
It end() { return _e; }
};
template<class It>
IteratorPair<It> iterator_pair(It b, It e)
{
return {b, e};
}
template<class T>
class PassthroughMath
{
public:
static
T inced(T v) { return ++v; }
};
// An iterator that just directly contains an integer-like value
// TODO port this once the new integer API happens
template<class T, class Math=PassthroughMath<T>>
class ValueIterator
{
T value;
public:
typedef std::forward_iterator_tag iterator_category;
typedef void difference_type;
typedef T value_type;
typedef void reference;
typedef void pointer;
public:
ValueIterator(T v)
: value(v)
{}
T operator *()
{
return value;
}
ValueIterator& operator++ ()
{
value = Math::inced(value);
return *this;
}
friend bool operator == (ValueIterator l, ValueIterator r)
{
return l.value == r.value;
}
friend bool operator != (ValueIterator l, ValueIterator r)
{
return !(l == r);
}
};
template<class T>
IteratorPair<ValueIterator<T>> value_range(T b, T e)
{
return {b, e};
}
template<class T, class F, class C>
class FilterIterator
{
F filter;
C *container;
using InnerIterator = decltype(std::begin(*container));
InnerIterator impl;
public:
void post_adv()
{
while (impl != std::end(*container))
{
if (filter(*impl))
break;
++impl;
}
}
FilterIterator(C *c, F f)
: filter(f), container(c), impl(std::begin(*c))
{
post_adv();
}
void operator ++()
{
++impl;
post_adv();
}
T operator *()
{
return *impl;
}
friend
bool operator != (FilterIterator l, FilterIterator)
{
return l.impl != std::end(*l.container);
}
};
template<class T>
bool is_truthy(T v)
{
return v;
}
template<class T, class F=decltype(is_truthy<T>)*, class C>
IteratorPair<FilterIterator<T, F, C>> filter_iterator(C *c, F f=is_truthy<T>)
{
return {FilterIterator<T, F, C>(c, f), FilterIterator<T, F, C>(c, f)};
}
} // namespace tmwa
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