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Diff: array_view.h
- Revision:
- 0:b47c2a7920c2
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/array_view.h Fri Mar 16 16:34:18 2018 +0000 @@ -0,0 +1,874 @@ +///\file + +/****************************************************************************** +The MIT License(MIT) + +Embedded Template Library. +https://github.com/ETLCPP/etl +https://www.etlcpp.com + +Copyright(c) 2017 jwellbelove + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files(the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and / or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions : + +The above copyright notice and this permission notice shall be included in all +copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +SOFTWARE. +******************************************************************************/ + +#ifndef __ETL_ARRAY_VIEW__ +#define __ETL_ARRAY_VIEW__ + +#include "platform.h" +#include "memory.h" +#include "iterator.h" +#include "error_handler.h" +#include "exception.h" +#include "nullptr.h" +#include "hash.h" + +#include <algorithm> + +///\defgroup array array +/// A wrapper for arrays +///\ingroup containers + +#undef ETL_FILE +#define ETL_FILE "41" + +namespace etl +{ + //*************************************************************************** + /// The base class for array_view exceptions. + //*************************************************************************** + class array_view_exception : public exception + { + public: + + array_view_exception(string_type reason_, string_type file_name_, numeric_type line_number_) + : exception(reason_, file_name_, line_number_) + { + } + }; + + //*************************************************************************** + ///\ingroup stack + /// The exception thrown when the index is out of bounds. + //*************************************************************************** + class array_view_bounds : public array_view_exception + { + public: + + array_view_bounds(string_type file_name_, numeric_type line_number_) + : array_view_exception(ETL_ERROR_TEXT("array_view:bounds", ETL_FILE"A"), file_name_, line_number_) + { + } + }; + + //*************************************************************************** + ///\ingroup stack + /// The exception thrown when the view is uninitialised. + //*************************************************************************** + class array_view_uninitialised : public array_view_exception + { + public: + + array_view_uninitialised(string_type file_name_, numeric_type line_number_) + : array_view_exception(ETL_ERROR_TEXT("array_view:uninitialised", ETL_FILE"B"), file_name_, line_number_) + { + } + }; + + //*************************************************************************** + /// Array view. + //*************************************************************************** + template <typename T> + class array_view + { + public: + + typedef T value_type; + typedef std::size_t size_type; + typedef T& reference; + typedef const T& const_reference; + typedef T* pointer; + typedef const T* const_pointer; + typedef T* iterator; + typedef const T* const_iterator; + typedef std::reverse_iterator<iterator> reverse_iterator; + typedef std::reverse_iterator<const_iterator> const_reverse_iterator; + + //************************************************************************* + /// Default constructor. + //************************************************************************* + array_view() + : mbegin(std::nullptr), + mend(std::nullptr) + { + } + + //************************************************************************* + /// Construct from std::array or etl::array or other type that supports + /// data() and size() member functions. + //************************************************************************* + template <typename TArray, + typename TDummy = typename etl::enable_if<!etl::is_same<T, TArray>::value, void>::type> + explicit array_view(TArray& a) + : mbegin(a.data()), + mend(a.data() + a.size()) + { + } + + //************************************************************************* + /// Construct from iterators + //************************************************************************* + template <typename TIterator, + typename TDummy = typename etl::enable_if<etl::is_random_iterator<TIterator>::value, void>::type> + array_view(TIterator begin_, TIterator end_) + : mbegin(etl::addressof(*begin_)), + mend(etl::addressof(*begin_) + std::distance(begin_, end_)) + { + } + + //************************************************************************* + /// Construct from C array + //************************************************************************* + template <typename TIterator, + typename TSize, + typename TDummy = typename etl::enable_if<etl::is_random_iterator<TIterator>::value, void>::type> + array_view(TIterator begin_, TSize size_) + : mbegin(etl::addressof(*begin_)), + mend(etl::addressof(*begin_) + size_) + { + } + + //************************************************************************* + /// Construct from C array + //************************************************************************* + template<const size_t ARRAY_SIZE> + explicit array_view(T(&begin_)[ARRAY_SIZE]) + : mbegin(begin_), + mend(begin_ + ARRAY_SIZE) + { + } + + //************************************************************************* + /// Copy constructor + //************************************************************************* + array_view(const array_view& other) + : mbegin(other.mbegin), + mend(other.mend) + { + } + + //************************************************************************* + /// Returns a reference to the first element. + //************************************************************************* + reference front() + { + return *mbegin; + } + + //************************************************************************* + /// Returns a const reference to the first element. + //************************************************************************* + const_reference front() const + { + return *mbegin; + } + + //************************************************************************* + /// Returns a reference to the last element. + //************************************************************************* + reference back() + { + return *(mend - 1); + } + + //************************************************************************* + /// Returns a const reference to the last element. + //************************************************************************* + const_reference back() const + { + return *(mend - 1); + } + + //************************************************************************* + /// Returns a pointer to the first element of the internal storage. + //************************************************************************* + pointer data() + { + return mbegin; + } + + //************************************************************************* + /// Returns a const pointer to the first element of the internal storage. + //************************************************************************* + const_pointer data() const + { + return mbegin; + } + + //************************************************************************* + /// Returns an iterator to the beginning of the array. + //************************************************************************* + iterator begin() + { + return mbegin; + } + + //************************************************************************* + /// Returns a const iterator to the beginning of the array. + //************************************************************************* + const_iterator begin() const + { + return mbegin; + } + + //************************************************************************* + /// Returns a const iterator to the beginning of the array. + //************************************************************************* + const_iterator cbegin() const + { + return mbegin; + } + + //************************************************************************* + /// Returns an iterator to the end of the array. + //************************************************************************* + iterator end() + { + return mend; + } + + //************************************************************************* + /// Returns a const iterator to the end of the array. + //************************************************************************* + const_iterator end() const + { + return mend; + } + + //************************************************************************* + // Returns a const iterator to the end of the array. + //************************************************************************* + const_iterator cend() const + { + return mend; + } + + //************************************************************************* + // Returns an reverse iterator to the reverse beginning of the array. + //************************************************************************* + reverse_iterator rbegin() + { + return reverse_iterator(mend); + } + + //************************************************************************* + /// Returns a const reverse iterator to the reverse beginning of the array. + //************************************************************************* + const_reverse_iterator rbegin() const + { + return const_reverse_iterator(mend); + } + + //************************************************************************* + /// Returns a const reverse iterator to the reverse beginning of the array. + //************************************************************************* + const_reverse_iterator crbegin() const + { + return const_reverse_iterator(mend); + } + + //************************************************************************* + /// Returns a reverse iterator to the end of the array. + //************************************************************************* + reverse_iterator rend() + { + return reverse_iterator(mbegin); + } + + //************************************************************************* + /// Returns a const reverse iterator to the end of the array. + //************************************************************************* + const_reverse_iterator rend() const + { + return const_reverse_iterator(mbegin); + } + + //************************************************************************* + /// Returns a const reverse iterator to the end of the array. + //************************************************************************* + const_reverse_iterator crend() const + { + return const_reverse_iterator(mbegin); + } + + //************************************************************************* + /// Returns <b>true</b> if the array size is zero. + //************************************************************************* + bool empty() const + { + return (mbegin == mend); + } + + //************************************************************************* + /// Returns the size of the array. + //************************************************************************* + size_t size() const + { + return (mend - mbegin); + } + + //************************************************************************* + /// Returns the maximum possible size of the array. + //************************************************************************* + size_t max_size() const + { + return size(); + } + + //************************************************************************* + /// Assign from a view. + //************************************************************************* + array_view& operator=(const array_view& other) + { + mbegin = other.mbegin; + mend = other.mend; + return *this; + } + + //************************************************************************* + /// Assign from iterators + //************************************************************************* + template <typename TIterator, + typename TDummy = typename etl::enable_if<etl::is_random_iterator<TIterator>::value, void>::type> + void assign(TIterator begin_, TIterator end_) + { + mbegin = etl::addressof(*begin_); + mend = etl::addressof(*begin_) + std::distance(begin_, end_); + } + + //************************************************************************* + /// Assign from iterator and size. + //************************************************************************* + template <typename TIterator, + typename TSize, + typename TDummy = typename etl::enable_if<etl::is_random_iterator<TIterator>::value, void>::type> + void assign(TIterator begin_, TSize size_) + { + mbegin = etl::addressof(*begin_); + mend = etl::addressof(*begin_) + size_; + } + + //************************************************************************* + /// Returns a reference to the indexed value. + //************************************************************************* + reference operator[](size_t i) + { + return mbegin[i]; + } + + //************************************************************************* + /// Returns a const reference to the indexed value. + //************************************************************************* + const_reference operator[](size_t i) const + { + return mbegin[i]; + } + + //************************************************************************* + /// Returns a reference to the indexed value. + //************************************************************************* + reference at(size_t i) + { + ETL_ASSERT((mbegin != std::nullptr && mend != std::nullptr), ETL_ERROR(array_view_uninitialised)); + ETL_ASSERT(i < size(), ETL_ERROR(array_view_bounds)); + return mbegin[i]; + } + + //************************************************************************* + /// Returns a const reference to the indexed value. + //************************************************************************* + const_reference at(size_t i) const + { + ETL_ASSERT((mbegin != std::nullptr && mend != std::nullptr), ETL_ERROR(array_view_uninitialised)); + ETL_ASSERT(i < size(), ETL_ERROR(array_view_bounds)); + return mbegin[i]; + } + + //************************************************************************* + /// Swaps with another array_view. + //************************************************************************* + void swap(array_view& other) + { + std::swap(mbegin, other.mbegin); + std::swap(mend, other.mend); + } + + //************************************************************************* + /// Shrinks the view by moving its start forward. + //************************************************************************* + void remove_prefix(size_type n) + { + mbegin += n; + } + + //************************************************************************* + /// Shrinks the view by moving its end backward. + //************************************************************************* + void remove_suffix(size_type n) + { + mend -= n; + } + + //************************************************************************* + /// Equality for array views. + //************************************************************************* + friend bool operator == (const array_view<T>& lhs, const array_view<T>& rhs) + { + return (lhs.size() == rhs.size()) && + std::equal(lhs.begin(), lhs.end(), rhs.begin()); + } + + //************************************************************************* + /// Inequality for array views. + //************************************************************************* + friend bool operator != (const array_view<T>& lhs, const array_view<T>& rhs) + { + return !(lhs == rhs); + } + + //************************************************************************* + /// Less-than for array views. + //************************************************************************* + friend bool operator < (const array_view<T>& lhs, const array_view<T>& rhs) + { + return std::lexicographical_compare(lhs.begin(), lhs.end(), rhs.begin(), rhs.end()); + } + + //************************************************************************* + /// Greater-than for array views. + //************************************************************************* + friend bool operator > (const array_view<T>& lhs, const array_view<T>& rhs) + { + return rhs < lhs; + } + + //************************************************************************* + /// Less-than-equal for array views. + //************************************************************************* + friend bool operator <= (const array_view<T>& lhs, const array_view<T>& rhs) + { + return !(lhs > rhs); + } + + //************************************************************************* + /// Greater-than-equal for array views. + //************************************************************************* + friend bool operator >= (const array_view<T>& lhs, const array_view<T>& rhs) + { + return !(lhs < rhs); + } + + private: + + T* mbegin; + T* mend; + }; + + //*************************************************************************** + /// Constant array view. + //*************************************************************************** + template <typename T> + class const_array_view + { + public: + + typedef T value_type; + typedef std::size_t size_type; + typedef const T& const_reference; + typedef const T* const_pointer; + typedef const T* const_iterator; + typedef std::reverse_iterator<const_iterator> const_reverse_iterator; + + //************************************************************************* + /// Default constructor. + //************************************************************************* + const_array_view() + : mbegin(std::nullptr), + mend(std::nullptr) + { + } + + //************************************************************************* + /// Construct from std::array or etl::array or other type that supports + /// data() and size() member functions. + //************************************************************************* + template <typename TArray, + typename TDummy = typename etl::enable_if<!etl::is_same<T, TArray>::value, void>::type> + explicit const_array_view(TArray& a) + : mbegin(a.data()), + mend(a.data() + a.size()) + { + } + + //************************************************************************* + /// Construct from iterators + //************************************************************************* + template <typename TIterator, + typename TDummy = typename etl::enable_if<etl::is_random_iterator<TIterator>::value, void>::type> + const_array_view(TIterator begin_, TIterator end_) + : mbegin(etl::addressof(*begin_)), + mend(etl::addressof(*begin_) + std::distance(begin_, end_)) + { + } + + //************************************************************************* + /// Construct from C array + //************************************************************************* + template <typename TIterator, + typename TSize, typename TDummy = typename etl::enable_if<etl::is_random_iterator<TIterator>::value, void>::type> + const_array_view(TIterator begin_, TSize size_) + : mbegin(etl::addressof(*begin_)), + mend(etl::addressof(*begin_) + size_) + { + } + + //************************************************************************* + /// Construct from C array + //************************************************************************* + template<const size_t ARRAY_SIZE> + explicit const_array_view(const T(&begin_)[ARRAY_SIZE]) + : mbegin(begin_), + mend(begin_ + ARRAY_SIZE) + { + } + + //************************************************************************* + /// Copy constructor + //************************************************************************* + const_array_view(const array_view<T>& other) + : mbegin(other.begin()), + mend(other.end()) + { + } + + //************************************************************************* + /// Copy constructor + //************************************************************************* + const_array_view(const const_array_view& other) + : mbegin(other.mbegin), + mend(other.mend) + { + } + + //************************************************************************* + /// Returns a const reference to the first element. + //************************************************************************* + const_reference front() const + { + return *mbegin; + } + + //************************************************************************* + /// Returns a const reference to the last element. + //************************************************************************* + const_reference back() const + { + return *(mend - 1); + } + + //************************************************************************* + /// Returns a const pointer to the first element of the internal storage. + //************************************************************************* + const_pointer data() const + { + return mbegin; + } + + //************************************************************************* + /// Returns a const iterator to the beginning of the array. + //************************************************************************* + const_iterator begin() const + { + return mbegin; + } + + //************************************************************************* + /// Returns a const iterator to the beginning of the array. + //************************************************************************* + const_iterator cbegin() const + { + return mbegin; + } + + //************************************************************************* + /// Returns a const iterator to the end of the array. + //************************************************************************* + const_iterator end() const + { + return mend; + } + + //************************************************************************* + // Returns a const iterator to the end of the array. + //************************************************************************* + const_iterator cend() const + { + return mend; + } + + //************************************************************************* + /// Returns a const reverse iterator to the reverse beginning of the array. + //************************************************************************* + const_reverse_iterator rbegin() const + { + return const_reverse_iterator(mend); + } + + //************************************************************************* + /// Returns a const reverse iterator to the reverse beginning of the array. + //************************************************************************* + const_reverse_iterator crbegin() const + { + return const_reverse_iterator(mend); + } + + //************************************************************************* + /// Returns a const reverse iterator to the end of the array. + //************************************************************************* + const_reverse_iterator rend() const + { + return const_reverse_iterator(mbegin); + } + + //************************************************************************* + /// Returns a const reverse iterator to the end of the array. + //************************************************************************* + const_reverse_iterator crend() const + { + return const_reverse_iterator(mbegin); + } + + //************************************************************************* + // Capacity + //************************************************************************* + + //************************************************************************* + /// Returns <b>true</b> if the array size is zero. + //************************************************************************* + bool empty() const + { + return (mbegin == mend); + } + + //************************************************************************* + /// Returns the size of the array. + //************************************************************************* + size_t size() const + { + return (mend - mbegin); + } + + //************************************************************************* + /// Returns the maximum possible size of the array. + //************************************************************************* + size_t max_size() const + { + return size(); + } + + //************************************************************************* + /// Assign from a view. + //************************************************************************* + const_array_view<T>& operator=(const const_array_view<T>& other) + { + mbegin = other.mbegin; + mend = other.mend; + return *this; + } + + //************************************************************************* + /// Assign from iterators + //************************************************************************* + template <typename TIterator, + typename TDummy = typename etl::enable_if<etl::is_random_iterator<TIterator>::value, void>::type> + void assign(TIterator begin_, TIterator end_) + { + mbegin = etl::addressof(*begin_); + mend = etl::addressof(*begin_) + std::distance(begin_, end_); + } + + //************************************************************************* + /// Assign from iterator and size. + //************************************************************************* + template <typename TIterator, + typename TSize, + typename TDummy = typename etl::enable_if<etl::is_random_iterator<TIterator>::value, void>::type> + void assign(TIterator begin_, TSize size_) + { + mbegin = etl::addressof(*begin_); + mend = etl::addressof(*begin_) + size_; + } + + //************************************************************************* + /// Returns a const reference to the indexed value. + //************************************************************************* + const_reference operator[](size_t i) const + { + return mbegin[i]; + } + + //************************************************************************* + /// Returns a const reference to the indexed value. + //************************************************************************* + const_reference at(size_t i) const + { + ETL_ASSERT((mbegin != std::nullptr && mend != std::nullptr), ETL_ERROR(array_view_uninitialised)); + ETL_ASSERT(i < size(), ETL_ERROR(array_view_bounds)); + return mbegin[i]; + } + + //************************************************************************* + /// Swaps with another array_view. + //************************************************************************* + void swap(const_array_view& other) + { + std::swap(mbegin, other.mbegin); + std::swap(mend, other.mend); + } + + //************************************************************************* + /// Shrinks the view by moving its start forward. + //************************************************************************* + void remove_prefix(size_type n) + { + mbegin += n; + } + + //************************************************************************* + /// Shrinks the view by moving its end backward. + //************************************************************************* + void remove_suffix(size_type n) + { + mend -= n; + } + + //************************************************************************* + /// Equality for array views. + //************************************************************************* + friend bool operator == (const const_array_view<T>& lhs, const const_array_view<T>& rhs) + { + return (lhs.size() == rhs.size()) && + std::equal(lhs.begin(), lhs.end(), rhs.begin()); + } + + //************************************************************************* + /// Inequality for array views. + //************************************************************************* + friend bool operator != (const const_array_view<T>& lhs, const const_array_view<T>& rhs) + { + return !(lhs == rhs); + } + + //************************************************************************* + /// Less-than for array views. + //************************************************************************* + friend bool operator < (const const_array_view<T>& lhs, const const_array_view<T>& rhs) + { + return std::lexicographical_compare(lhs.begin(), lhs.end(), rhs.begin(), rhs.end()); + } + + //************************************************************************* + /// Greater-than for array views. + //************************************************************************* + friend bool operator > (const const_array_view<T>& lhs, const const_array_view<T>& rhs) + { + return rhs < lhs; + } + + //************************************************************************* + /// Less-than-equal for array views. + //************************************************************************* + friend bool operator <= (const const_array_view<T>& lhs, const const_array_view<T>& rhs) + { + return !(lhs > rhs); + } + + //************************************************************************* + /// Greater-than-equal for array views. + //************************************************************************* + friend bool operator >= (const const_array_view<T>& lhs, const const_array_view<T>& rhs) + { + return !(lhs < rhs); + } + + private: + + const T* mbegin; + const T* mend; + }; + + //************************************************************************* + /// Hash function. + //************************************************************************* +#if ETL_8BIT_SUPPORT + template <typename T> + struct hash<etl::array_view<T> > + { + size_t operator()(const etl::array_view<T>& view) const + { + return etl::__private_hash__::generic_hash<size_t>(reinterpret_cast<const uint8_t*>(&view[0]), + reinterpret_cast<const uint8_t*>(&view[view.size()])); + } + }; + + template <typename T> + struct hash<etl::const_array_view<T> > + { + size_t operator()(const etl::const_array_view<T>& view) const + { + return etl::__private_hash__::generic_hash<size_t>(reinterpret_cast<const uint8_t*>(&view[0]), + reinterpret_cast<const uint8_t*>(&view[view.size()])); + } + }; +#endif +} + +//************************************************************************* +/// Swaps the values. +//************************************************************************* +template <typename T> +void swap(etl::array_view<T>& lhs, etl::array_view<T>& rhs) +{ + lhs.swap(rhs); +} + +//************************************************************************* +/// Swaps the values. +//************************************************************************* +template <typename T> +void swap(etl::const_array_view<T>& lhs, etl::const_array_view<T>& rhs) +{ + lhs.swap(rhs); +} + +#undef ETL_FILE + +#endif + +