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azerothcore-wotlk/src/common/Containers.h

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3.5 KiB
C++

/*
* Copyright (C) 2016+ AzerothCore <www.azerothcore.org>
* Copyright (C) 2008-2016 TrinityCore <http://www.trinitycore.org/>
* Copyright (C) 2005-2009 MaNGOS <http://getmangos.com/>
*/
#ifndef ACORE_CONTAINERS_H
#define ACORE_CONTAINERS_H
#include "Define.h"
#include <algorithm>
#include <exception>
#include <iterator>
#include <utility>
#include <list>
#include <vector>
//! Because circular includes are bad
extern uint32 urand(uint32 min, uint32 max);
extern uint32 urandweighted(size_t count, double const* chances);
namespace acore
{
template<class T>
constexpr inline T* AddressOrSelf(T* ptr)
{
return ptr;
}
template<class T>
constexpr inline T* AddressOrSelf(T& not_ptr)
{
return std::addressof(not_ptr);
}
template <class T>
class CheckedBufferOutputIterator
{
public:
using iterator_category = std::output_iterator_tag;
using value_type = void;
using pointer = T*;
using reference = T&;
using difference_type = std::ptrdiff_t;
CheckedBufferOutputIterator(T* buf, size_t n) : _buf(buf), _end(buf + n) {}
T& operator*() const { check(); return *_buf; }
CheckedBufferOutputIterator& operator++() { check(); ++_buf; return *this; }
CheckedBufferOutputIterator operator++(int) { CheckedBufferOutputIterator v = *this; operator++(); return v; }
[[nodiscard]] size_t remaining() const { return (_end - _buf); }
private:
T* _buf;
T* _end;
void check() const
{
if (!(_buf < _end))
throw std::out_of_range("index");
}
};
namespace Containers
{
template<class T>
void RandomResizeList(std::list<T>& list, uint32 size)
{
size_t list_size = list.size();
while (list_size > size)
{
typename std::list<T>::iterator itr = list.begin();
std::advance(itr, urand(0, list_size - 1));
list.erase(itr);
--list_size;
}
}
template<class T, class Predicate>
void RandomResizeList(std::list<T>& list, Predicate& predicate, uint32 size)
{
//! First use predicate filter
std::list<T> listCopy;
for (typename std::list<T>::iterator itr = list.begin(); itr != list.end(); ++itr)
if (predicate(*itr))
listCopy.push_back(*itr);
if (size)
RandomResizeList(listCopy, size);
list = listCopy;
}
/* Select a random element from a container. Note: make sure you explicitly empty check the container */
template <class C> typename C::value_type const& SelectRandomContainerElement(C const& container)
{
typename C::const_iterator it = container.begin();
std::advance(it, urand(0, container.size() - 1));
return *it;
}
/* Select a random element from a container where each element has a different chance to be selected. */
template <class C> typename C::value_type const& SelectRandomWeightedContainerElement(C const& container, std::vector<double> const& weights)
{
typename C::const_iterator it = container.begin();
std::advance(it, urandweighted(weights.size(), weights.data()));
return *it;
}
}
//! namespace Containers
}
//! namespace acore
#endif //! #ifdef ACORE_CONTAINERS_H