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Diffstat (limited to '3rdParty/Boost/src/boost/signals2/detail/auto_buffer.hpp')
-rw-r--r-- | 3rdParty/Boost/src/boost/signals2/detail/auto_buffer.hpp | 1138 |
1 files changed, 1138 insertions, 0 deletions
diff --git a/3rdParty/Boost/src/boost/signals2/detail/auto_buffer.hpp b/3rdParty/Boost/src/boost/signals2/detail/auto_buffer.hpp new file mode 100644 index 0000000..bf12e69 --- /dev/null +++ b/3rdParty/Boost/src/boost/signals2/detail/auto_buffer.hpp @@ -0,0 +1,1138 @@ +// Copyright Thorsten Ottosen, 2009. +// Distributed under the Boost Software License, Version 1.0. (See +// accompanying file LICENSE_1_0.txt or copy at +// http://www.boost.org/LICENSE_1_0.txt) + +#ifndef BOOST_SIGNALS2_DETAIL_AUTO_BUFFER_HPP_25_02_2009 +#define BOOST_SIGNALS2_DETAIL_AUTO_BUFFER_HPP_25_02_2009 + +#include <boost/detail/workaround.hpp> + +#if defined(_MSC_VER) +# pragma once +#endif + +#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400) +#pragma warning(push) +#pragma warning(disable:4996) +#endif + +#include <boost/assert.hpp> +#include <boost/iterator/reverse_iterator.hpp> +#include <boost/iterator/iterator_traits.hpp> +#include <boost/mpl/if.hpp> +#include <boost/multi_index/detail/scope_guard.hpp> +#include <boost/swap.hpp> +#include <boost/throw_exception.hpp> +#include <boost/type_traits/aligned_storage.hpp> +#include <boost/type_traits/alignment_of.hpp> +#include <boost/type_traits/has_nothrow_copy.hpp> +#include <boost/type_traits/has_nothrow_assign.hpp> +#include <boost/type_traits/has_trivial_assign.hpp> +#include <boost/type_traits/has_trivial_constructor.hpp> +#include <boost/type_traits/has_trivial_destructor.hpp> +#include <algorithm> +#include <cstring> +#include <iterator> +#include <memory> +#include <stdexcept> + +namespace boost +{ +namespace signals2 +{ +namespace detail +{ + // + // Policies for creating the stack buffer. + // + template< unsigned N > + struct store_n_objects + { + BOOST_STATIC_CONSTANT( unsigned, value = N ); + }; + + template< unsigned N > + struct store_n_bytes + { + BOOST_STATIC_CONSTANT( unsigned, value = N ); + }; + + namespace auto_buffer_detail + { + template< class Policy, class T > + struct compute_buffer_size + { + BOOST_STATIC_CONSTANT( unsigned, value = Policy::value * sizeof(T) ); + }; + + template< unsigned N, class T > + struct compute_buffer_size< store_n_bytes<N>, T > + { + BOOST_STATIC_CONSTANT( unsigned, value = N ); + }; + + template< class Policy, class T > + struct compute_buffer_objects + { + BOOST_STATIC_CONSTANT( unsigned, value = Policy::value ); + }; + + template< unsigned N, class T > + struct compute_buffer_objects< store_n_bytes<N>, T > + { + BOOST_STATIC_CONSTANT( unsigned, value = N / sizeof(T) ); + }; + } + + struct default_grow_policy + { + template< class SizeType > + static SizeType new_capacity( SizeType capacity ) + { + // + // @remark: we grow the capacity quite agressively. + // this is justified since we aim to minimize + // heap-allocations, and because we mostly use + // the buffer locally. + return capacity * 4u; + } + + template< class SizeType > + static bool should_shrink( SizeType size, SizeType capacity ) + { + // + // @remark: when defining a new grow policy, one might + // choose that if the waated space is less + // than a certain percentage, then it is of + // little use to shrink. + // + return true; + } + }; + + template< class T, + class StackBufferPolicy = store_n_objects<256>, + class GrowPolicy = default_grow_policy, + class Allocator = std::allocator<T> > + class auto_buffer; + + + + template + < + class T, + class StackBufferPolicy, + class GrowPolicy, + class Allocator + > + class auto_buffer : Allocator + { + private: + enum { N = auto_buffer_detail:: + compute_buffer_objects<StackBufferPolicy,T>::value }; + + BOOST_STATIC_CONSTANT( bool, is_stack_buffer_empty = N == 0u ); + + typedef auto_buffer<T, store_n_objects<0>, GrowPolicy, Allocator> + local_buffer; + + public: + typedef Allocator allocator_type; + typedef T value_type; + typedef typename Allocator::size_type size_type; + typedef typename Allocator::difference_type difference_type; + typedef T* pointer; + typedef typename Allocator::pointer allocator_pointer; + typedef const T* const_pointer; + typedef T& reference; + typedef const T& const_reference; + typedef pointer iterator; + typedef const_pointer const_iterator; + typedef boost::reverse_iterator<iterator> reverse_iterator; + typedef boost::reverse_iterator<const_iterator> const_reverse_iterator; + typedef typename boost::mpl::if_c< boost::has_trivial_assign<T>::value + && sizeof(T) <= sizeof(long double), + const value_type, + const_reference >::type + optimized_const_reference; + private: + + pointer allocate( size_type capacity_arg ) + { + if( capacity_arg > N ) + return &*get_allocator().allocate( capacity_arg ); + else + return static_cast<T*>( members_.address() ); + } + + void deallocate( pointer where, size_type capacity_arg ) + { + if( capacity_arg <= N ) + return; + get_allocator().deallocate( allocator_pointer(where), capacity_arg ); + } + + template< class I > + static void copy_impl( I begin, I end, pointer where, std::random_access_iterator_tag ) + { + copy_rai( begin, end, where, boost::has_trivial_assign<T>() ); + } + + static void copy_rai( const T* begin, const T* end, + pointer where, const boost::true_type& ) + { + std::memcpy( where, begin, sizeof(T) * std::distance(begin,end) ); + } + + template< class I, bool b > + static void copy_rai( I begin, I end, + pointer where, const boost::integral_constant<bool, b>& ) + { + std::uninitialized_copy( begin, end, where ); + } + + template< class I > + static void copy_impl( I begin, I end, pointer where, std::bidirectional_iterator_tag ) + { + std::uninitialized_copy( begin, end, where ); + } + + template< class I > + static void copy_impl( I begin, I end, pointer where ) + { + copy_impl( begin, end, where, + typename std::iterator_traits<I>::iterator_category() ); + } + + template< class I, class I2 > + static void assign_impl( I begin, I end, I2 where ) + { + assign_impl( begin, end, where, boost::has_trivial_assign<T>() ); + } + + template< class I, class I2 > + static void assign_impl( I begin, I end, I2 where, const boost::true_type& ) + { + std::memcpy( where, begin, sizeof(T) * std::distance(begin,end) ); + } + + template< class I, class I2 > + static void assign_impl( I begin, I end, I2 where, const boost::false_type& ) + { + for( ; begin != end; ++begin, ++where ) + *where = *begin; + } + + void unchecked_push_back_n( size_type n, const boost::true_type& ) + { + std::uninitialized_fill( end(), end() + n, T() ); + size_ += n; + } + + void unchecked_push_back_n( size_type n, const boost::false_type& ) + { + for( size_type i = 0u; i < n; ++i ) + unchecked_push_back(); + } + + void auto_buffer_destroy( pointer where, const boost::false_type& ) + { + (*where).~T(); + } + + void auto_buffer_destroy( pointer, const boost::true_type& ) + { } + + void auto_buffer_destroy( pointer where ) + { + auto_buffer_destroy( where, boost::has_trivial_destructor<T>() ); + } + + void destroy_back_n( size_type n, const boost::false_type& ) + { + BOOST_ASSERT( n > 0 ); + pointer buffer = buffer_ + size_ - 1u; + pointer new_end = buffer - n; + for( ; buffer > new_end; --buffer ) + auto_buffer_destroy( buffer ); + } + + void destroy_back_n( size_type n, const boost::true_type& ) + { } + + void destroy_back_n( size_type n ) + { + destroy_back_n( n, boost::has_trivial_destructor<T>() ); + } + + void auto_buffer_destroy( const boost::false_type& x ) + { + if( size_ ) + destroy_back_n( size_, x ); + deallocate( buffer_, members_.capacity_ ); + } + + void auto_buffer_destroy( const boost::true_type& ) + { + deallocate( buffer_, members_.capacity_ ); + } + + pointer move_to_new_buffer( size_type new_capacity, const boost::false_type& ) + { + pointer new_buffer = allocate( new_capacity ); // strong + boost::multi_index::detail::scope_guard guard = + boost::multi_index::detail::make_obj_guard( *this, + &auto_buffer::deallocate, + new_buffer, + new_capacity ); + copy_impl( begin(), end(), new_buffer ); // strong + guard.dismiss(); // nothrow + return new_buffer; + } + + pointer move_to_new_buffer( size_type new_capacity, const boost::true_type& ) + { + pointer new_buffer = allocate( new_capacity ); // strong + copy_impl( begin(), end(), new_buffer ); // nothrow + return new_buffer; + } + + void reserve_impl( size_type new_capacity ) + { + pointer new_buffer = move_to_new_buffer( new_capacity, + boost::has_nothrow_copy<T>() ); + (*this).~auto_buffer(); + buffer_ = new_buffer; + members_.capacity_ = new_capacity; + BOOST_ASSERT( size_ <= members_.capacity_ ); + } + + size_type new_capacity_impl( size_type n ) + { + BOOST_ASSERT( n > members_.capacity_ ); + size_type new_capacity = GrowPolicy::new_capacity( members_.capacity_ ); + // @todo: consider to check for allocator.max_size() + return (std::max)(new_capacity,n); + } + + static void swap_helper( auto_buffer& l, auto_buffer& r, + const boost::true_type& ) + { + BOOST_ASSERT( l.is_on_stack() && r.is_on_stack() ); + + auto_buffer temp( l.begin(), l.end() ); + assign_impl( r.begin(), r.end(), l.begin() ); + assign_impl( temp.begin(), temp.end(), r.begin() ); + boost::swap( l.size_, r.size_ ); + boost::swap( l.members_.capacity_, r.members_.capacity_ ); + } + + static void swap_helper( auto_buffer& l, auto_buffer& r, + const boost::false_type& ) + { + BOOST_ASSERT( l.is_on_stack() && r.is_on_stack() ); + size_type min_size = (std::min)(l.size_,r.size_); + size_type max_size = (std::max)(l.size_,r.size_); + size_type diff = max_size - min_size; + auto_buffer* smallest = l.size_ == min_size ? &l : &r; + auto_buffer* largest = smallest == &l ? &r : &l; + + // @remark: the implementation below is not as fast + // as it could be if we assumed T had a default + // constructor. + + size_type i = 0u; + for( ; i < min_size; ++i ) + boost::swap( (*smallest)[i], (*largest)[i] ); + + for( ; i < max_size; ++i ) + smallest->unchecked_push_back( (*largest)[i] ); + + largest->pop_back_n( diff ); + boost::swap( l.members_.capacity_, r.members_.capacity_ ); + } + + void one_sided_swap( auto_buffer& temp ) // nothrow + { + BOOST_ASSERT( !temp.is_on_stack() ); + this->~auto_buffer(); + // @remark: must be nothrow + get_allocator() = temp.get_allocator(); + members_.capacity_ = temp.members_.capacity_; + buffer_ = temp.buffer_; + BOOST_ASSERT( temp.size_ >= size_ + 1u ); + size_ = temp.size_; + temp.buffer_ = 0; + BOOST_ASSERT( temp.is_valid() ); + } + + template< class I > + void insert_impl( const_iterator before, I begin_arg, I end_arg, + std::input_iterator_tag ) + { + for( ; begin_arg != end_arg; ++begin_arg ) + { + before = insert( before, *begin_arg ); + ++before; + } + } + + void grow_back( size_type n, const boost::true_type& ) + { + BOOST_ASSERT( size_ + n <= members_.capacity_ ); + size_ += n; + } + + void grow_back( size_type n, const boost::false_type& ) + { + unchecked_push_back_n(n); + } + + void grow_back( size_type n ) + { + grow_back( n, boost::has_trivial_constructor<T>() ); + } + + void grow_back_one( const boost::true_type& ) + { + BOOST_ASSERT( size_ + 1 <= members_.capacity_ ); + size_ += 1; + } + + void grow_back_one( const boost::false_type& ) + { + unchecked_push_back(); + } + + void grow_back_one() + { + grow_back_one( boost::has_trivial_constructor<T>() ); + } + + template< class I > + void insert_impl( const_iterator before, I begin_arg, I end_arg, + std::forward_iterator_tag ) + { + difference_type n = std::distance(begin_arg, end_arg); + + if( size_ + n <= members_.capacity_ ) + { + bool is_back_insertion = before == cend(); + if( !is_back_insertion ) + { + grow_back( n ); + iterator where = const_cast<T*>(before); + std::copy( before, cend() - n, where + n ); + assign_impl( begin_arg, end_arg, where ); + } + else + { + unchecked_push_back( begin_arg, end_arg ); + } + BOOST_ASSERT( is_valid() ); + return; + } + + auto_buffer temp( new_capacity_impl( size_ + n ) ); + temp.unchecked_push_back( cbegin(), before ); + temp.unchecked_push_back( begin_arg, end_arg ); + temp.unchecked_push_back( before, cend() ); + one_sided_swap( temp ); + BOOST_ASSERT( is_valid() ); + } + + public: + bool is_valid() const // invariant + { + // @remark: allowed for N==0 and when + // using a locally instance + // in insert()/one_sided_swap() + if( buffer_ == 0 ) + return true; + + if( members_.capacity_ < N ) + return false; + + if( !is_on_stack() && members_.capacity_ <= N ) + return false; + + if( buffer_ == members_.address() ) + if( members_.capacity_ > N ) + return false; + + if( size_ > members_.capacity_ ) + return false; + + return true; + } + + auto_buffer() + : members_( N ), + buffer_( static_cast<T*>(members_.address()) ), + size_( 0u ) + { + BOOST_ASSERT( is_valid() ); + } + + auto_buffer( const auto_buffer& r ) + : members_( (std::max)(r.size_,size_type(N)) ), + buffer_( allocate( members_.capacity_ ) ), + size_( 0 ) + { + copy_impl( r.begin(), r.end(), buffer_ ); + size_ = r.size_; + BOOST_ASSERT( is_valid() ); + } + + auto_buffer& operator=( const auto_buffer& r ) // basic + { + if( this == &r ) + return *this; + + difference_type diff = size_ - r.size_; + if( diff >= 0 ) + { + pop_back_n( static_cast<size_type>(diff) ); + assign_impl( r.begin(), r.end(), begin() ); + } + else + { + if( members_.capacity_ >= r.size() ) + { + unchecked_push_back_n( static_cast<size_type>(-diff) ); + assign_impl( r.begin(), r.end(), begin() ); + } + else + { + // @remark: we release memory as early as possible + // since we only give the basic guarantee + (*this).~auto_buffer(); + buffer_ = 0; + pointer new_buffer = allocate( r.size() ); + boost::multi_index::detail::scope_guard guard = + boost::multi_index::detail::make_obj_guard( *this, + &auto_buffer::deallocate, + new_buffer, + r.size() ); + copy_impl( r.begin(), r.end(), new_buffer ); + guard.dismiss(); + buffer_ = new_buffer; + members_.capacity_ = r.size(); + size_ = members_.capacity_; + } + } + + BOOST_ASSERT( size() == r.size() ); + BOOST_ASSERT( is_valid() ); + return *this; + } + + explicit auto_buffer( size_type capacity_arg ) + : members_( (std::max)(capacity_arg, size_type(N)) ), + buffer_( allocate(members_.capacity_) ), + size_( 0 ) + { + BOOST_ASSERT( is_valid() ); + } + + auto_buffer( size_type size_arg, optimized_const_reference init_value ) + : members_( (std::max)(size_arg, size_type(N)) ), + buffer_( allocate(members_.capacity_) ), + size_( 0 ) + { + std::uninitialized_fill( buffer_, buffer_ + size_arg, init_value ); + size_ = size_arg; + BOOST_ASSERT( is_valid() ); + } + + auto_buffer( size_type capacity_arg, const allocator_type& a ) + : allocator_type( a ), + members_( (std::max)(capacity_arg, size_type(N)) ), + buffer_( allocate(members_.capacity_) ), + size_( 0 ) + { + BOOST_ASSERT( is_valid() ); + } + + auto_buffer( size_type size_arg, optimized_const_reference init_value, + const allocator_type& a ) + : allocator_type( a ), + members_( (std::max)(size_arg, size_type(N)) ), + buffer_( allocate(members_.capacity_) ), + size_( 0 ) + { + std::uninitialized_fill( buffer_, buffer_ + size_arg, init_value ); + size_ = size_arg; + BOOST_ASSERT( is_valid() ); + } + + template< class ForwardIterator > + auto_buffer( ForwardIterator begin_arg, ForwardIterator end_arg ) + : + members_( std::distance(begin_arg, end_arg) ), + buffer_( allocate(members_.capacity_) ), + size_( 0 ) + { + copy_impl( begin_arg, end_arg, buffer_ ); + size_ = members_.capacity_; + if( members_.capacity_ < N ) + members_.capacity_ = N; + BOOST_ASSERT( is_valid() ); + } + + template< class ForwardIterator > + auto_buffer( ForwardIterator begin_arg, ForwardIterator end_arg, + const allocator_type& a ) + : allocator_type( a ), + members_( std::distance(begin_arg, end_arg) ), + buffer_( allocate(members_.capacity_) ), + size_( 0 ) + { + copy_impl( begin_arg, end_arg, buffer_ ); + size_ = members_.capacity_; + if( members_.capacity_ < N ) + members_.capacity_ = N; + BOOST_ASSERT( is_valid() ); + } + + ~auto_buffer() + { + BOOST_ASSERT( is_valid() ); + if( buffer_ ) // do we need this check? Yes, but only + // for N = 0u + local instances in one_sided_swap() + auto_buffer_destroy( boost::has_trivial_destructor<T>() ); + } + + public: + bool empty() const + { + return size_ == 0; + } + + bool full() const + { + return size_ == members_.capacity_; + } + + bool is_on_stack() const + { + return members_.capacity_ <= N; + } + + size_type size() const + { + return size_; + } + + size_type capacity() const + { + return members_.capacity_; + } + + public: + pointer data() + { + return buffer_; + } + + const_pointer data() const + { + return buffer_; + } + + allocator_type& get_allocator() + { + return static_cast<allocator_type&>(*this); + } + + const allocator_type& get_allocator() const + { + return static_cast<const allocator_type&>(*this); + } + + public: + iterator begin() + { + return buffer_; + } + + const_iterator begin() const + { + return buffer_; + } + + iterator end() + { + return buffer_ + size_; + } + + const_iterator end() const + { + return buffer_ + size_; + } + + reverse_iterator rbegin() + { + return reverse_iterator(end()); + } + + const_reverse_iterator rbegin() const + { + return const_reverse_iterator(end()); + } + + reverse_iterator rend() + { + return reverse_iterator(begin()); + } + + const_reverse_iterator rend() const + { + return const_reverse_iterator(begin()); + } + + const_iterator cbegin() const + { + return const_cast<const auto_buffer*>(this)->begin(); + } + + const_iterator cend() const + { + return const_cast<const auto_buffer*>(this)->end(); + } + + const_reverse_iterator crbegin() const + { + return const_cast<const auto_buffer*>(this)->rbegin(); + } + + const_reverse_iterator crend() const + { + return const_cast<const auto_buffer*>(this)->rend(); + } + + public: + reference front() + { + return buffer_[0]; + } + + optimized_const_reference front() const + { + return buffer_[0]; + } + + reference back() + { + return buffer_[size_-1]; + } + + optimized_const_reference back() const + { + return buffer_[size_-1]; + } + + reference operator[]( size_type n ) + { + BOOST_ASSERT( n < size_ ); + return buffer_[n]; + } + + optimized_const_reference operator[]( size_type n ) const + { + BOOST_ASSERT( n < size_ ); + return buffer_[n]; + } + + void unchecked_push_back() + { + BOOST_ASSERT( !full() ); + new (buffer_ + size_) T; + ++size_; + } + + void unchecked_push_back_n( size_type n ) + { + BOOST_ASSERT( size_ + n <= members_.capacity_ ); + unchecked_push_back_n( n, boost::has_trivial_assign<T>() ); + } + + void unchecked_push_back( optimized_const_reference x ) // non-growing + { + BOOST_ASSERT( !full() ); + new (buffer_ + size_) T( x ); + ++size_; + } + + template< class ForwardIterator > + void unchecked_push_back( ForwardIterator begin_arg, + ForwardIterator end_arg ) // non-growing + { + BOOST_ASSERT( size_ + std::distance(begin_arg, end_arg) <= members_.capacity_ ); + copy_impl( begin_arg, end_arg, buffer_ + size_ ); + size_ += std::distance(begin_arg, end_arg); + } + + void reserve_precisely( size_type n ) + { + BOOST_ASSERT( members_.capacity_ >= N ); + + if( n <= members_.capacity_ ) + return; + reserve_impl( n ); + BOOST_ASSERT( members_.capacity_ == n ); + } + + void reserve( size_type n ) // strong + { + BOOST_ASSERT( members_.capacity_ >= N ); + + if( n <= members_.capacity_ ) + return; + + reserve_impl( new_capacity_impl( n ) ); + BOOST_ASSERT( members_.capacity_ >= n ); + } + + void push_back() + { + if( size_ != members_.capacity_ ) + { + unchecked_push_back(); + } + else + { + reserve( size_ + 1u ); + unchecked_push_back(); + } + } + + void push_back( optimized_const_reference x ) + { + if( size_ != members_.capacity_ ) + { + unchecked_push_back( x ); + } + else + { + reserve( size_ + 1u ); + unchecked_push_back( x ); + } + } + + template< class ForwardIterator > + void push_back( ForwardIterator begin_arg, ForwardIterator end_arg ) + { + difference_type diff = std::distance(begin_arg, end_arg); + if( size_ + diff > members_.capacity_ ) + reserve( size_ + diff ); + unchecked_push_back( begin_arg, end_arg ); + } + + iterator insert( const_iterator before, optimized_const_reference x ) // basic + { + // @todo: consider if we want to support x in 'this' + if( size_ < members_.capacity_ ) + { + bool is_back_insertion = before == cend(); + iterator where = const_cast<T*>(before); + + if( !is_back_insertion ) + { + grow_back_one(); + std::copy( before, cend() - 1u, where + 1u ); + *where = x; + BOOST_ASSERT( is_valid() ); + } + else + { + unchecked_push_back( x ); + } + return where; + } + + auto_buffer temp( new_capacity_impl( size_ + 1u ) ); + temp.unchecked_push_back( cbegin(), before ); + iterator result = temp.end(); + temp.unchecked_push_back( x ); + temp.unchecked_push_back( before, cend() ); + one_sided_swap( temp ); + BOOST_ASSERT( is_valid() ); + return result; + } + + void insert( const_iterator before, size_type n, + optimized_const_reference x ) + { + // @todo: see problems above + if( size_ + n <= members_.capacity_ ) + { + grow_back( n ); + iterator where = const_cast<T*>(before); + std::copy( before, cend() - n, where + n ); + std::fill( where, where + n, x ); + BOOST_ASSERT( is_valid() ); + return; + } + + auto_buffer temp( new_capacity_impl( size_ + n ) ); + temp.unchecked_push_back( cbegin(), before ); + std::uninitialized_fill_n( temp.end(), n, x ); + temp.size_ += n; + temp.unchecked_push_back( before, cend() ); + one_sided_swap( temp ); + BOOST_ASSERT( is_valid() ); + } + + template< class ForwardIterator > + void insert( const_iterator before, + ForwardIterator begin_arg, ForwardIterator end_arg ) // basic + { + typedef typename std::iterator_traits<ForwardIterator> + ::iterator_category category; + insert_impl( before, begin_arg, end_arg, category() ); + } + + void pop_back() + { + BOOST_ASSERT( !empty() ); + auto_buffer_destroy( buffer_ + size_ - 1, boost::has_trivial_destructor<T>() ); + --size_; + } + + void pop_back_n( size_type n ) + { + BOOST_ASSERT( n <= size_ ); + if( n ) + { + destroy_back_n( n ); + size_ -= n; + } + } + + void clear() + { + pop_back_n( size_ ); + } + + iterator erase( const_iterator where ) + { + BOOST_ASSERT( !empty() ); + BOOST_ASSERT( cbegin() <= where ); + BOOST_ASSERT( cend() > where ); + + unsigned elements = cend() - where - 1u; + + if( elements > 0u ) + { + const_iterator start = where + 1u; + std::copy( start, start + elements, + const_cast<T*>(where) ); + } + pop_back(); + BOOST_ASSERT( !full() ); + iterator result = const_cast<T*>( where ); + BOOST_ASSERT( result <= end() ); + return result; + } + + iterator erase( const_iterator from, const_iterator to ) + { + BOOST_ASSERT( !(std::distance(from,to)>0) || + !empty() ); + BOOST_ASSERT( cbegin() <= from ); + BOOST_ASSERT( cend() >= to ); + + unsigned elements = std::distance(to,cend()); + + if( elements > 0u ) + { + BOOST_ASSERT( elements > 0u ); + std::copy( to, to + elements, + const_cast<T*>(from) ); + } + pop_back_n( std::distance(from,to) ); + BOOST_ASSERT( !full() ); + iterator result = const_cast<T*>( from ); + BOOST_ASSERT( result <= end() ); + return result; + } + + void shrink_to_fit() + { + if( is_on_stack() || !GrowPolicy::should_shrink(size_,members_.capacity_) ) + return; + + reserve_impl( size_ ); + members_.capacity_ = (std::max)(size_type(N),members_.capacity_); + BOOST_ASSERT( is_on_stack() || size_ == members_.capacity_ ); + BOOST_ASSERT( !is_on_stack() || size_ <= members_.capacity_ ); + } + + pointer uninitialized_grow( size_type n ) // strong + { + if( size_ + n <= members_.capacity_ ) + reserve( size_ + n ); + + pointer res = end(); + size_ += n; + return res; + } + + void uninitialized_shrink( size_type n ) // nothrow + { + // @remark: test for wrap-around + BOOST_ASSERT( size_ - n <= members_.capacity_ ); + size_ -= n; + } + + void uninitialized_resize( size_type n ) + { + if( n > size() ) + uninitialized_grow( n - size() ); + else if( n < size() ) + uninitialized_shrink( size() - n ); + + BOOST_ASSERT( size() == n ); + } + + // nothrow - if both buffer are on the heap, or + // - if one buffer is on the heap and one has + // 'has_allocated_buffer() == false', or + // - if copy-construction cannot throw + // basic - otherwise (better guarantee impossible) + // requirement: the allocator must be no-throw-swappable + void swap( auto_buffer& r ) + { + bool on_stack = is_on_stack(); + bool r_on_stack = r.is_on_stack(); + bool both_on_heap = !on_stack && !r_on_stack; + if( both_on_heap ) + { + boost::swap( get_allocator(), r.get_allocator() ); + boost::swap( members_.capacity_, r.members_.capacity_ ); + boost::swap( buffer_, r.buffer_ ); + boost::swap( size_, r.size_ ); + BOOST_ASSERT( is_valid() ); + BOOST_ASSERT( r.is_valid() ); + return; + } + + BOOST_ASSERT( on_stack || r_on_stack ); + bool exactly_one_on_stack = (on_stack && !r_on_stack) || + (!on_stack && r_on_stack); + + // + // Remark: we now know that we can copy into + // the unused stack buffer. + // + if( exactly_one_on_stack ) + { + auto_buffer* one_on_stack = on_stack ? this : &r; + auto_buffer* other = on_stack ? &r : this; + pointer new_buffer = static_cast<T*>(other->members_.address()); + copy_impl( one_on_stack->begin(), one_on_stack->end(), + new_buffer ); // strong + one_on_stack->~auto_buffer(); // nothrow + boost::swap( get_allocator(), r.get_allocator() ); // assume nothrow + boost::swap( members_.capacity_, r.members_.capacity_ ); + boost::swap( size_, r.size_ ); + one_on_stack->buffer_ = other->buffer_; + other->buffer_ = new_buffer; + BOOST_ASSERT( other->is_on_stack() ); + BOOST_ASSERT( !one_on_stack->is_on_stack() ); + BOOST_ASSERT( is_valid() ); + BOOST_ASSERT( r.is_valid() ); + return; + } + + BOOST_ASSERT( on_stack && r_on_stack ); + swap_helper( *this, r, boost::has_trivial_assign<T>() ); + BOOST_ASSERT( is_valid() ); + BOOST_ASSERT( r.is_valid() ); + } + + private: + typedef boost::aligned_storage< N * sizeof(T), + boost::alignment_of<T>::value > + storage; + + struct members_type : storage /* to enable EBO */ + { + size_type capacity_; + + members_type( size_type capacity ) + : capacity_(capacity) + { } + + void* address() const + { return const_cast<storage&>(static_cast<const storage&>(*this)).address(); } + }; + + members_type members_; + pointer buffer_; + size_type size_; + + }; + + template< class T, class SBP, class GP, class A > + inline void swap( auto_buffer<T,SBP,GP,A>& l, auto_buffer<T,SBP,GP,A>& r ) + { + l.swap( r ); + } + + template< class T, class SBP, class GP, class A > + inline bool operator==( const auto_buffer<T,SBP,GP,A>& l, + const auto_buffer<T,SBP,GP,A>& r ) + { + if( l.size() != r.size() ) + return false; + return std::equal( l.begin(), l.end(), r.begin() ); + } + + template< class T, class SBP, class GP, class A > + inline bool operator!=( const auto_buffer<T,SBP,GP,A>& l, + const auto_buffer<T,SBP,GP,A>& r ) + { + return !(l == r); + } + + template< class T, class SBP, class GP, class A > + inline bool operator<( const auto_buffer<T,SBP,GP,A>& l, + const auto_buffer<T,SBP,GP,A>& r ) + { + return std::lexicographical_compare( l.begin(), l.end(), + r.begin(), r.end() ); + } + + template< class T, class SBP, class GP, class A > + inline bool operator>( const auto_buffer<T,SBP,GP,A>& l, + const auto_buffer<T,SBP,GP,A>& r ) + { + return (r < l); + } + + template< class T, class SBP, class GP, class A > + inline bool operator<=( const auto_buffer<T,SBP,GP,A>& l, + const auto_buffer<T,SBP,GP,A>& r ) + { + return !(r > l); + } + + template< class T, class SBP, class GP, class A > + inline bool operator>=( const auto_buffer<T,SBP,GP,A>& l, + const auto_buffer<T,SBP,GP,A>& r ) + { + return !(l < r); + } + +} // namespace detail +} // namespace signals2 +} + +#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400) +#pragma warning(pop) +#endif + +#endif |