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plf_stack.h
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plf_stack.h
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// Copyright (c) 2024, Matthew Bentley (mattreecebentley@gmail.com) www.plflib.org
// zLib license (https://www.zlib.net/zlib_license.html):
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgement in the product documentation would be
// appreciated but is not required.
// 2. Altered source versions must be plainly marked as such, and must not be
// misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.
#ifndef PLF_STACK_H
#define PLF_STACK_H
// Compiler-specific defines:
// Define default cases before possibly redefining:
#define PLF_NOEXCEPT throw()
#define PLF_NOEXCEPT_ALLOCATOR
#define PLF_CONSTEXPR
#define PLF_CONSTFUNC
#define PLF_EXCEPTIONS_SUPPORT
#if ((defined(__clang__) || defined(__GNUC__)) && !defined(__EXCEPTIONS)) || (defined(_MSC_VER) && !defined(_CPPUNWIND))
#undef PLF_EXCEPTIONS_SUPPORT
#include <exception> // std::terminate
#endif
#if defined(_MSC_VER) && !defined(__clang__) && !defined(__GNUC__)
// Suppress incorrect (unfixed MSVC bug) warnings re: constant expressions in constexpr-if statements
#pragma warning ( push )
#pragma warning ( disable : 4127 )
#if _MSC_VER >= 1600
#define PLF_MOVE_SEMANTICS_SUPPORT
#endif
#if _MSC_VER >= 1700
#define PLF_TYPE_TRAITS_SUPPORT
#define PLF_ALLOCATOR_TRAITS_SUPPORT
#endif
#if _MSC_VER >= 1800
#define PLF_VARIADICS_SUPPORT // Variadics, in this context, means both variadic templates and variadic macros are supported
#define PLF_DEFAULT_TEMPLATE_ARGUMENT_SUPPORT
#define PLF_INITIALIZER_LIST_SUPPORT
#endif
#if _MSC_VER >= 1900
#define PLF_ALIGNMENT_SUPPORT
#undef PLF_NOEXCEPT
#undef PLF_NOEXCEPT_ALLOCATOR
#define PLF_NOEXCEPT noexcept
#define PLF_NOEXCEPT_ALLOCATOR noexcept(noexcept(allocator_type()))
#define PLF_IS_ALWAYS_EQUAL_SUPPORT
#endif
#if defined(_MSVC_LANG) && (_MSVC_LANG >= 201703L)
#undef PLF_CONSTEXPR
#define PLF_CONSTEXPR constexpr
#endif
#if defined(_MSVC_LANG) && (_MSVC_LANG >= 202002L) && _MSC_VER >= 1929
#define PLF_CPP20_SUPPORT
#undef PLF_CONSTFUNC
#define PLF_CONSTFUNC constexpr
#endif
#elif defined(__cplusplus) && __cplusplus >= 201103L // C++11 support, at least
#if defined(__GNUC__) && defined(__GNUC_MINOR__) && !defined(__clang__) // If compiler is GCC/G++
#if (__GNUC__ == 4 && __GNUC_MINOR__ >= 3) || __GNUC__ > 4
#define PLF_MOVE_SEMANTICS_SUPPORT
#define PLF_VARIADICS_SUPPORT
#endif
#if (__GNUC__ == 4 && __GNUC_MINOR__ >= 4) || __GNUC__ > 4
#define PLF_DEFAULT_TEMPLATE_ARGUMENT_SUPPORT
#define PLF_INITIALIZER_LIST_SUPPORT
#endif
#if (__GNUC__ == 4 && __GNUC_MINOR__ >= 6) || __GNUC__ > 4
#undef PLF_NOEXCEPT
#undef PLF_NOEXCEPT_ALLOCATOR
#define PLF_NOEXCEPT noexcept
#define PLF_NOEXCEPT_ALLOCATOR noexcept(noexcept(allocator_type()))
#endif
#if (__GNUC__ == 4 && __GNUC_MINOR__ >= 7) || __GNUC__ > 4
#define PLF_ALLOCATOR_TRAITS_SUPPORT
#endif
#if (__GNUC__ == 4 && __GNUC_MINOR__ >= 8) || __GNUC__ > 4
#define PLF_ALIGNMENT_SUPPORT
#endif
#if __GNUC__ >= 5 // GCC v4.9 and below do not support std::is_trivially_copyable
#define PLF_TYPE_TRAITS_SUPPORT
#endif
#if __GNUC__ > 6
#define PLF_IS_ALWAYS_EQUAL_SUPPORT
#endif
#elif defined(__clang__) && !defined(__GLIBCXX__) && !defined(_LIBCPP_CXX03_LANG) && __clang_major__ >= 3
#define PLF_DEFAULT_TEMPLATE_ARGUMENT_SUPPORT
#define PLF_ALLOCATOR_TRAITS_SUPPORT
#define PLF_TYPE_TRAITS_SUPPORT
#if __has_feature(cxx_alignas) && __has_feature(cxx_alignof)
#define PLF_ALIGNMENT_SUPPORT
#endif
#if __has_feature(cxx_noexcept)
#undef PLF_NOEXCEPT
#undef PLF_NOEXCEPT_ALLOCATOR
#define PLF_NOEXCEPT noexcept
#define PLF_NOEXCEPT_ALLOCATOR noexcept(noexcept(allocator_type()))
#define PLF_IS_ALWAYS_EQUAL_SUPPORT
#endif
#if __has_feature(cxx_rvalue_references) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
#define PLF_MOVE_SEMANTICS_SUPPORT
#endif
#if __has_feature(cxx_variadic_templates) && !defined(_LIBCPP_HAS_NO_VARIADICS)
#define PLF_VARIADICS_SUPPORT
#endif
#if (__clang_major__ == 3 && __clang_minor__ >= 1) || __clang_major__ > 3
#define PLF_INITIALIZER_LIST_SUPPORT
#endif
#elif defined(__GLIBCXX__) // Using another compiler type with libstdc++ - we are assuming full c++11 compliance for compiler - which may not be true
#define PLF_DEFAULT_TEMPLATE_ARGUMENT_SUPPORT
#if __GLIBCXX__ >= 20080606
#define PLF_MOVE_SEMANTICS_SUPPORT
#define PLF_VARIADICS_SUPPORT
#endif
#if __GLIBCXX__ >= 20090421
#define PLF_INITIALIZER_LIST_SUPPORT
#endif
#if __GLIBCXX__ >= 20120322
#define PLF_ALLOCATOR_TRAITS_SUPPORT
#undef PLF_NOEXCEPT
#undef PLF_NOEXCEPT_ALLOCATOR
#define PLF_NOEXCEPT noexcept
#define PLF_NOEXCEPT_ALLOCATOR noexcept(noexcept(allocator_type()))
#endif
#if __GLIBCXX__ >= 20130322
#define PLF_ALIGNMENT_SUPPORT
#endif
#if __GLIBCXX__ >= 20150422 // libstdc++ v4.9 and below do not support std::is_trivially_copyable
#define PLF_TYPE_TRAITS_SUPPORT
#endif
#if __GLIBCXX__ >= 20160111
#define PLF_IS_ALWAYS_EQUAL_SUPPORT
#endif
#elif defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) // Special case for checking C++11 support with libCPP
#if !defined(_LIBCPP_HAS_NO_VARIADICS)
#define PLF_VARIADICS_SUPPORT
#endif
#else // Assume type traits and initializer support for other compilers and standard library implementations
#define PLF_DEFAULT_TEMPLATE_ARGUMENT_SUPPORT
#define PLF_MOVE_SEMANTICS_SUPPORT
#define PLF_VARIADICS_SUPPORT
#define PLF_TYPE_TRAITS_SUPPORT
#define PLF_ALLOCATOR_TRAITS_SUPPORT
#define PLF_ALIGNMENT_SUPPORT
#define PLF_INITIALIZER_LIST_SUPPORT
#undef PLF_NOEXCEPT
#undef PLF_NOEXCEPT_ALLOCATOR
#define PLF_NOEXCEPT noexcept
#define PLF_NOEXCEPT_ALLOCATOR noexcept(noexcept(allocator_type()))
#define PLF_IS_ALWAYS_EQUAL_SUPPORT
#endif
#if __cplusplus >= 201703L && ((defined(__clang__) && ((__clang_major__ == 3 && __clang_minor__ == 9) || __clang_major__ > 3)) || (defined(__GNUC__) && __GNUC__ >= 7) || (!defined(__clang__) && !defined(__GNUC__))) // assume correct C++17 implementation for non-gcc/clang compilers
#undef PLF_CONSTEXPR
#define PLF_CONSTEXPR constexpr
#endif
#if __cplusplus > 201704L && ((((defined(__clang__) && !defined(__APPLE_CC__) && __clang_major__ >= 14) || (defined(__GNUC__) && (__GNUC__ > 11 || (__GNUC__ == 11 && __GNUC_MINOR__ > 0)))) && ((defined(_LIBCPP_VERSION) && _LIBCPP_VERSION >= 14) || (defined(__GLIBCXX__) && __GLIBCXX__ >= 201806L))) || (!defined(__clang__) && !defined(__GNUC__)))
#define PLF_CPP20_SUPPORT
#undef PLF_CONSTFUNC
#define PLF_CONSTFUNC constexpr
#endif
#endif
#if defined(PLF_IS_ALWAYS_EQUAL_SUPPORT) && defined(PLF_MOVE_SEMANTICS_SUPPORT) && defined(PLF_ALLOCATOR_TRAITS_SUPPORT) && (__cplusplus >= 201703L || (defined(_MSVC_LANG) && (_MSVC_LANG >= 201703L)))
#define PLF_NOEXCEPT_MOVE_ASSIGN(the_allocator) noexcept(std::allocator_traits<the_allocator>::propagate_on_container_move_assignment::value || std::allocator_traits<the_allocator>::is_always_equal::value)
#define PLF_NOEXCEPT_SWAP(the_allocator) noexcept(std::allocator_traits<the_allocator>::propagate_on_container_swap::value || std::allocator_traits<the_allocator>::is_always_equal::value)
#else
#define PLF_NOEXCEPT_MOVE_ASSIGN(the_allocator)
#define PLF_NOEXCEPT_SWAP(the_allocator)
#endif
#ifdef PLF_ALLOCATOR_TRAITS_SUPPORT
#ifdef PLF_VARIADICS_SUPPORT
#define PLF_CONSTRUCT(the_allocator, allocator_instance, location, ...) std::allocator_traits<the_allocator>::construct(allocator_instance, location, __VA_ARGS__)
#else
#define PLF_CONSTRUCT(the_allocator, allocator_instance, location, data) std::allocator_traits<the_allocator>::construct(allocator_instance, location, data)
#endif
#define PLF_DESTROY(the_allocator, allocator_instance, location) std::allocator_traits<the_allocator>::destroy(allocator_instance, location)
#define PLF_ALLOCATE(the_allocator, allocator_instance, size, hint) std::allocator_traits<the_allocator>::allocate(allocator_instance, size, hint)
#define PLF_DEALLOCATE(the_allocator, allocator_instance, location, size) std::allocator_traits<the_allocator>::deallocate(allocator_instance, location, size)
#else
#ifdef PLF_VARIADICS_SUPPORT
#define PLF_CONSTRUCT(the_allocator, allocator_instance, location, ...) (allocator_instance).construct(location, __VA_ARGS__)
#else
#define PLF_CONSTRUCT(the_allocator, allocator_instance, location, data) (allocator_instance).construct(location, data)
#endif
#define PLF_DESTROY(the_allocator, allocator_instance, location) (allocator_instance).destroy(location)
#define PLF_ALLOCATE(the_allocator, allocator_instance, size, hint) (allocator_instance).allocate(size, hint)
#define PLF_DEALLOCATE(the_allocator, allocator_instance, location, size) (allocator_instance).deallocate(location, size)
#endif
#include <cstring> // memset, memcpy
#include <cassert> // assert
#include <limits> // std::numeric_limits
#include <memory> // std::uninitialized_copy, std::allocator
#include <stdexcept> // std::length_error
#include <utility> // std::move, std::swap
#ifdef PLF_TYPE_TRAITS_SUPPORT
#include <cstddef> // offsetof, used in blank()
#include <type_traits> // std::is_trivially_destructible
#endif
#ifdef PLF_CPP20_SUPPORT
#include <compare> // std::to_address
#endif
namespace plf
{
// std:: tool replacements for C++03/98/11 support:
#ifndef PLF_TOOLS
#define PLF_TOOLS
template <bool condition, class T = void>
struct enable_if
{
typedef T type;
};
template <class T>
struct enable_if<false, T>
{};
template <bool flag, class is_true, class is_false> struct conditional;
template <class is_true, class is_false> struct conditional<true, is_true, is_false>
{
typedef is_true type;
};
template <class is_true, class is_false> struct conditional<false, is_true, is_false>
{
typedef is_false type;
};
template <class element_type>
struct less
{
bool operator() (const element_type &a, const element_type &b) const PLF_NOEXCEPT
{
return a < b;
}
};
template<class element_type>
struct equal_to
{
const element_type &value;
explicit equal_to(const element_type &store_value) PLF_NOEXCEPT:
value(store_value)
{}
bool operator() (const element_type &compare_value) const PLF_NOEXCEPT
{
return value == compare_value;
}
};
// To enable conversion to void * when allocator supplies non-raw pointers:
template <class source_pointer_type>
static PLF_CONSTFUNC void * void_cast(const source_pointer_type source_pointer) PLF_NOEXCEPT
{
#ifdef PLF_CPP20_SUPPORT
return static_cast<void *>(std::to_address(source_pointer));
#else
return static_cast<void *>(&*source_pointer);
#endif
}
#ifdef PLF_MOVE_SEMANTICS_SUPPORT
template <class iterator_type>
static PLF_CONSTFUNC std::move_iterator<iterator_type> make_move_iterator(iterator_type it)
{
return std::move_iterator<iterator_type>(std::move(it));
}
#endif
enum priority { performance = 1, memory_use = 4};
#endif
template <class element_type, class allocator_type = std::allocator<element_type> > class stack : private allocator_type // Empty base class optimisation - inheriting allocator functions
{
public:
// Standard container typedefs:
typedef element_type value_type;
#ifdef PLF_ALLOCATOR_TRAITS_SUPPORT
typedef typename std::allocator_traits<allocator_type>::size_type size_type;
typedef element_type & reference;
typedef const element_type & const_reference;
typedef typename std::allocator_traits<allocator_type>::pointer pointer;
typedef typename std::allocator_traits<allocator_type>::const_pointer const_pointer;
#else
typedef typename allocator_type::size_type size_type;
typedef typename allocator_type::reference reference;
typedef typename allocator_type::const_reference const_reference;
typedef typename allocator_type::pointer pointer;
typedef typename allocator_type::const_pointer const_pointer;
#endif
private:
struct group; // Forward declaration for typedefs below
#ifdef PLF_ALLOCATOR_TRAITS_SUPPORT
typedef typename std::allocator_traits<allocator_type>::template rebind_alloc<group> group_allocator_type;
typedef typename std::allocator_traits<group_allocator_type>::pointer group_pointer_type;
typedef typename std::allocator_traits<allocator_type>::pointer element_pointer_type;
#else
typedef typename allocator_type::template rebind<group>::other group_allocator_type;
typedef typename group_allocator_type::pointer group_pointer_type;
typedef typename allocator_type::pointer element_pointer_type;
#endif
struct group : private allocator_type
{
const element_pointer_type elements;
group_pointer_type next_group, previous_group;
const element_pointer_type end; // One-past the back element
#ifdef PLF_VARIADICS_SUPPORT
group(const size_type elements_per_group, const group_pointer_type previous = NULL):
elements(PLF_ALLOCATE(allocator_type, *this, elements_per_group, (previous == NULL) ? 0 : previous->elements)),
next_group(NULL),
previous_group(previous),
end(elements + elements_per_group)
{}
#else
// This is a hack around the fact that allocator_type::construct only supports copy construction in C++03 and copy elision does not occur on the vast majority of compilers in this circumstance. And to avoid running out of memory (and performance loss) from allocating the same block twice, we're allocating in the copy constructor.
group(const size_type elements_per_group, const group_pointer_type previous = NULL) PLF_NOEXCEPT:
elements(NULL),
next_group(reinterpret_cast<group_pointer_type>(elements_per_group)),
previous_group(previous),
end(NULL)
{}
// Not a real copy constructor ie. actually a move constructor. Only used for allocator.construct in C++03 for reasons stated above:
group(const group &source):
allocator_type(source),
elements(PLF_ALLOCATE(allocator_type, *this, reinterpret_cast<size_type>(source.next_group), (source.previous_group == NULL) ? 0 : source.previous_group->elements)),
next_group(NULL),
previous_group(source.previous_group),
end(elements + reinterpret_cast<size_type>(source.next_group))
{}
#endif
~group() PLF_NOEXCEPT
{
// Null check not necessary (for empty group and copied group as above) as deallocate will do it's own null check.
PLF_DEALLOCATE(allocator_type, *this, elements, static_cast<size_type>(end - elements));
}
};
group_pointer_type current_group, first_group; // current group is location of top pointer, first_group is 'front' group, saves performance for ~stack etc
element_pointer_type top_element, start_element, end_element; // start_element/end_element cache current_group->end/elements for better performance
size_type total_size, total_capacity, min_block_capacity;
struct ebco_pair : group_allocator_type // Packaging the group allocator with the least-used member variable, for empty-base-class optimization
{
size_type max_block_capacity;
ebco_pair(const size_type max_elements, const allocator_type &alloc) PLF_NOEXCEPT:
group_allocator_type(alloc),
max_block_capacity(max_elements)
{};
} group_allocator_pair;
void check_capacities_conformance(const size_type min, const size_type max) const
{
if (min < 2 || min > max || max > (default_max_block_capacity()))
{
#ifdef PLF_EXCEPTIONS_SUPPORT
throw std::length_error("Supplied memory block capacities outside of allowable ranges");
#else
std::terminate();
#endif
}
}
public:
static PLF_CONSTFUNC size_type default_min_block_capacity() PLF_NOEXCEPT
{
return (sizeof(element_type) * 8 > (sizeof(stack) + sizeof(group)) * 2) ? 8 : (((sizeof(stack) + sizeof(group)) * 2) / sizeof(element_type)) + 1;
}
static PLF_CONSTFUNC size_type default_max_block_capacity() PLF_NOEXCEPT
{
return std::numeric_limits<size_type>::max() / 2;
}
// Default constructor:
PLF_CONSTFUNC stack() PLF_NOEXCEPT_ALLOCATOR:
current_group(NULL),
first_group(NULL),
top_element(NULL),
start_element(NULL),
end_element(NULL),
total_size(0),
total_capacity(0),
min_block_capacity(default_min_block_capacity()),
group_allocator_pair(default_max_block_capacity(), *this)
{}
// Allocator-extended constructor:
explicit stack(const allocator_type &alloc):
allocator_type(alloc),
current_group(NULL),
first_group(NULL),
top_element(NULL),
start_element(NULL),
end_element(NULL),
total_size(0),
total_capacity(0),
min_block_capacity(default_min_block_capacity()),
group_allocator_pair(default_max_block_capacity(), alloc)
{}
// Constructor with minimum & maximum group size parameters:
stack(const size_type min, const size_type max = default_max_block_capacity()):
current_group(NULL),
first_group(NULL),
top_element(NULL),
start_element(NULL),
end_element(NULL),
total_size(0),
total_capacity(0),
min_block_capacity(min),
group_allocator_pair(max, *this)
{
check_capacities_conformance(min, max);
}
// Allocator-extended constructor with minimum & maximum group size parameters:
stack(const size_type min, const size_type max, const allocator_type &alloc):
allocator_type(alloc),
current_group(NULL),
first_group(NULL),
top_element(NULL),
start_element(NULL),
end_element(NULL),
total_size(0),
total_capacity(0),
min_block_capacity(min),
group_allocator_pair(max, alloc)
{
check_capacities_conformance(min, max);
}
private:
void allocate_new_group(const size_type capacity, const group_pointer_type previous_group)
{
previous_group->next_group = PLF_ALLOCATE(group_allocator_type, group_allocator_pair, 1, previous_group);
#ifdef PLF_EXCEPTIONS_SUPPORT
try
{
#ifdef PLF_VARIADICS_SUPPORT
PLF_CONSTRUCT(group_allocator_type, group_allocator_pair, previous_group->next_group, capacity, previous_group);
#else
PLF_CONSTRUCT(group_allocator_type, group_allocator_pair, previous_group->next_group, group(capacity, previous_group));
#endif
}
catch (...)
{
PLF_DEALLOCATE(group_allocator_type, group_allocator_pair, previous_group->next_group, 1);
throw;
}
#else
#ifdef PLF_VARIADICS_SUPPORT
PLF_CONSTRUCT(group_allocator_type, group_allocator_pair, previous_group->next_group, capacity, previous_group);
#else
PLF_CONSTRUCT(group_allocator_type, group_allocator_pair, previous_group->next_group, group(capacity, previous_group));
#endif
#endif
total_capacity += capacity;
}
void deallocate_group(const group_pointer_type the_group) PLF_NOEXCEPT
{
PLF_DESTROY(group_allocator_type, group_allocator_pair, the_group);
PLF_DEALLOCATE(group_allocator_type, group_allocator_pair, the_group, 1);
}
void initialize()
{
first_group = current_group = PLF_ALLOCATE(group_allocator_type, group_allocator_pair, 1, 0);
#ifdef PLF_EXCEPTIONS_SUPPORT
try
{
#ifdef PLF_VARIADICS_SUPPORT
PLF_CONSTRUCT(group_allocator_type, group_allocator_pair, first_group, min_block_capacity);
#else
PLF_CONSTRUCT(group_allocator_type, group_allocator_pair, first_group, group(min_block_capacity));
#endif
}
catch (...)
{
PLF_DEALLOCATE(group_allocator_type, group_allocator_pair, first_group, 1);
first_group = current_group = NULL;
throw;
}
#else
#ifdef PLF_VARIADICS_SUPPORT
PLF_CONSTRUCT(group_allocator_type, group_allocator_pair, first_group, min_block_capacity);
#else
PLF_CONSTRUCT(group_allocator_type, group_allocator_pair, first_group, group(min_block_capacity));
#endif
#endif
start_element = top_element = first_group->elements;
end_element = first_group->end;
total_capacity = min_block_capacity;
}
void progress_to_next_group() // used by push/emplace
{
if (current_group->next_group == NULL) // no reserved groups or groups left over from previous pops, allocate new group
{
allocate_new_group((total_size < group_allocator_pair.max_block_capacity) ? total_size : group_allocator_pair.max_block_capacity, current_group);
}
current_group = current_group->next_group;
start_element = top_element = current_group->elements;
end_element = current_group->end;
}
void copy_from_source(const stack &source) // Note: this function is only called on an empty un-initialize()'d stack
{
assert(&source != this);
if (source.total_size == 0) return;
group_pointer_type current_copy_group = source.first_group;
const group_pointer_type end_copy_group = source.current_group;
if (source.total_size <= group_allocator_pair.max_block_capacity) // most common case
{
const size_type original_min_block_capacity = min_block_capacity;
min_block_capacity = source.total_size;
initialize();
min_block_capacity = original_min_block_capacity;
// Copy groups to this stack:
while (current_copy_group != end_copy_group)
{
std::uninitialized_copy(current_copy_group->elements, current_copy_group->end, top_element);
top_element += current_copy_group->end - current_copy_group->elements;
current_copy_group = current_copy_group->next_group;
}
// Handle special case of last group:
std::uninitialized_copy(source.start_element, source.top_element + 1, top_element);
top_element += source.top_element - source.start_element; // This should make top_element == the last "pushed" element, rather than the one past it
end_element = top_element + 1; // Since we have created a single group where capacity == size, this is correct
total_size = source.total_size;
}
else // uncommon edge case, so not optimising:
{
min_block_capacity = group_allocator_pair.max_block_capacity;
while (current_copy_group != end_copy_group)
{
for (element_pointer_type element_to_copy = current_copy_group->elements; element_to_copy != current_copy_group->end; ++element_to_copy)
{
push(*element_to_copy);
}
current_copy_group = current_copy_group->next_group;
}
// Handle special case of last group:
for (element_pointer_type element_to_copy = source.start_element; element_to_copy != source.top_element + 1; ++element_to_copy)
{
push(*element_to_copy);
}
min_block_capacity = source.min_block_capacity;
}
}
void destroy_all_data() PLF_NOEXCEPT
{
#ifdef PLF_TYPE_TRAITS_SUPPORT
if PLF_CONSTEXPR(!std::is_trivially_destructible<element_type>::value) // Avoid iteration for trivially-destructible types eg. POD, structs, classes with empty destructor.
#endif // If compiler doesn't support traits, iterate regardless - trivial destructors will not be called, hopefully compiler will optimise this loop out for POD types
{
if (total_size != 0)
{
while (first_group != current_group)
{
const element_pointer_type past_end = first_group->end;
for (element_pointer_type element_pointer = first_group->elements; element_pointer != past_end; ++element_pointer)
{
PLF_DESTROY(allocator_type, *this, element_pointer);
}
const group_pointer_type next_group = first_group->next_group;
deallocate_group(first_group);
first_group = next_group;
}
// Special case for current group:
const element_pointer_type past_end = top_element + 1;
for (element_pointer_type element_pointer = start_element; element_pointer != past_end; ++element_pointer)
{
PLF_DESTROY(allocator_type, *this, element_pointer);
}
first_group = first_group->next_group; // To further process reserved groups in the following loop
deallocate_group(current_group);
}
}
total_size = 0;
while (first_group != NULL)
{
current_group = first_group;
first_group = first_group->next_group;
deallocate_group(current_group);
}
}
void blank() PLF_NOEXCEPT
{
#ifdef PLF_IS_ALWAYS_EQUAL_SUPPORT // allocator_traits and type_traits always available when is_always_equal is available
if PLF_CONSTEXPR (std::is_standard_layout<stack>::value && std::allocator_traits<allocator_type>::is_always_equal::value && std::is_trivial<group_pointer_type>::value && std::is_trivial<element_pointer_type>::value) // if all pointer types are trivial, we can just nuke it from orbit with memset (NULL is always 0 in C++):
{
std::memset(static_cast<void *>(this), 0, offsetof(stack, min_block_capacity));
}
else
#endif
{
current_group = NULL;
first_group = NULL;
top_element = NULL;
start_element = NULL;
end_element = NULL;
total_size = 0;
total_capacity = 0;
}
}
public:
// Copy constructor:
stack(const stack &source):
#if defined(__cplusplus) && __cplusplus >= 201103L
allocator_type(std::allocator_traits<allocator_type>::select_on_container_copy_construction(source)),
#else
allocator_type(source),
#endif
current_group(NULL),
first_group(NULL),
top_element(NULL),
start_element(NULL),
end_element(NULL),
total_size(0),
total_capacity(0),
min_block_capacity(source.min_block_capacity),
group_allocator_pair(source.group_allocator_pair.max_block_capacity, *this)
{
copy_from_source(source);
}
// Allocator-extended copy constructor:
stack(const stack &source, const allocator_type &alloc):
allocator_type(alloc),
current_group(NULL),
first_group(NULL),
top_element(NULL),
start_element(NULL),
end_element(NULL),
total_size(0),
total_capacity(0),
min_block_capacity(source.min_block_capacity),
group_allocator_pair(source.group_allocator_pair.max_block_capacity, alloc)
{
copy_from_source(source);
}
#ifdef PLF_MOVE_SEMANTICS_SUPPORT
// move constructor
stack(stack &&source) PLF_NOEXCEPT:
allocator_type(std::move(static_cast<allocator_type &>(source))),
current_group(std::move(source.current_group)),
first_group(std::move(source.first_group)),
top_element(std::move(source.top_element)),
start_element(std::move(source.start_element)),
end_element(std::move(source.end_element)),
total_size(source.total_size),
total_capacity(source.total_capacity),
min_block_capacity(source.min_block_capacity),
group_allocator_pair(source.group_allocator_pair.max_block_capacity, source)
{
source.blank();
}
// allocator-extended move constructor
stack(stack &&source, const allocator_type &alloc):
allocator_type(alloc),
current_group(std::move(source.current_group)),
first_group(std::move(source.first_group)),
top_element(std::move(source.top_element)),
start_element(std::move(source.start_element)),
end_element(std::move(source.end_element)),
total_size(source.total_size),
total_capacity(source.total_capacity),
min_block_capacity(source.min_block_capacity),
group_allocator_pair(source.group_allocator_pair.max_block_capacity, alloc)
{
source.blank();
}
#endif
~stack() PLF_NOEXCEPT
{
destroy_all_data();
}
void push(const element_type &element)
{
if (top_element == NULL)
{
initialize();
}
else if (++top_element == end_element) // ie. out of capacity for current element memory block
{
progress_to_next_group();
}
// Create element:
#ifdef PLF_EXCEPTIONS_SUPPORT
#ifdef PLF_TYPE_TRAITS_SUPPORT
if PLF_CONSTEXPR (std::is_nothrow_copy_constructible<element_type>::value)
{
PLF_CONSTRUCT(allocator_type, *this, top_element, element);
}
else
#endif
{
try
{
PLF_CONSTRUCT(allocator_type, *this, top_element, element);
}
catch (...)
{
if (top_element == start_element && current_group != first_group) // for post-initialize push
{
current_group = current_group->previous_group;
start_element = current_group->elements;
top_element = current_group->end - 1;
}
else
{
--top_element;
}
throw;
}
}
#else
PLF_CONSTRUCT(allocator_type, *this, top_element, element);
#endif
++total_size;
}
#ifdef PLF_MOVE_SEMANTICS_SUPPORT
// Note: the reason for code duplication from non-move push, as opposed to using std::forward for both, was because most compilers didn't actually create as-optimal code in that strategy. Also C++03 compatibility.
void push(element_type &&element)
{
if (top_element == NULL)
{
initialize();
}
else if (++top_element == end_element)
{
progress_to_next_group();
}
#ifdef PLF_EXCEPTIONS_SUPPORT
#ifdef PLF_TYPE_TRAITS_SUPPORT
if PLF_CONSTEXPR (std::is_nothrow_move_constructible<element_type>::value)
{
PLF_CONSTRUCT(allocator_type, *this, top_element, std::move(element));
}
else
#endif
{
try
{
PLF_CONSTRUCT(allocator_type, *this, top_element, std::move(element));
}
catch (...)
{
if (top_element == start_element && current_group != first_group)
{
current_group = current_group->previous_group;
start_element = current_group->elements;
top_element = current_group->end - 1;
}
else
{
--top_element;
}
throw;
}
}
#else
PLF_CONSTRUCT(allocator_type, *this, top_element, std::move(element));
#endif
++total_size;
}
#endif
#ifdef PLF_VARIADICS_SUPPORT
template<typename... arguments>
void emplace(arguments &&... parameters)
{
if (top_element == NULL)
{
initialize();
}
else if (++top_element == end_element)
{
progress_to_next_group();
}
#ifdef PLF_EXCEPTIONS_SUPPORT
#ifdef PLF_TYPE_TRAITS_SUPPORT
if PLF_CONSTEXPR (std::is_nothrow_constructible<element_type>::value)
{
PLF_CONSTRUCT(allocator_type, *this, top_element, std::forward<arguments>(parameters)...);
}
else
#endif
{
try
{
PLF_CONSTRUCT(allocator_type, *this, top_element, std::forward<arguments>(parameters)...);
}
catch (...)
{
if (top_element == start_element && current_group != first_group)
{
current_group = current_group->previous_group;
start_element = current_group->elements;
top_element = current_group->end - 1;
}
else
{
--top_element;
}
throw;
}
}
#else
PLF_CONSTRUCT(allocator_type, *this, top_element, std::forward<arguments>(parameters)...);
#endif
++total_size;
}
#endif
reference top() const // Exception may occur if stack is empty in release mode
{
assert(total_size != 0);
return *top_element;
}
void pop() // Exception may occur if stack is empty
{
assert(total_size != 0);
#ifdef PLF_TYPE_TRAITS_SUPPORT
if PLF_CONSTEXPR (!std::is_trivially_destructible<element_type>::value)
#endif
{
PLF_DESTROY(allocator_type, *this, top_element);
}
if ((--total_size != 0) & (top_element-- == start_element))
{ // ie. is start element, but not first group in stack
current_group = current_group->previous_group;
start_element = current_group->elements;
end_element = current_group->end;
top_element = end_element - 1;