dash/src/immer/flex_vector.hpp
Alexander Block a370bbfe3d Update immer library to current master (0a718d2d76bab6ebdcf43de943bd6c7d2dbfe2f9) (#2821)
* Update immer library to current master (0a718d2d76bab6ebdcf43de943bd6c7d2dbfe2f9)

* Temporary fix for alignof(std::max_align_t) on MinGW 32bit builds

See https://github.com/arximboldi/immer/issues/78
2019-04-01 14:10:49 +03:00

503 lines
16 KiB
C++

//
// immer: immutable data structures for C++
// Copyright (C) 2016, 2017, 2018 Juan Pedro Bolivar Puente
//
// This software is distributed under the Boost Software License, Version 1.0.
// See accompanying file LICENSE or copy at http://boost.org/LICENSE_1_0.txt
//
#pragma once
#include <immer/detail/rbts/rrbtree.hpp>
#include <immer/detail/rbts/rrbtree_iterator.hpp>
#include <immer/memory_policy.hpp>
namespace immer {
template <typename T,
typename MP,
detail::rbts::bits_t B,
detail::rbts::bits_t BL>
class vector;
template <typename T,
typename MP,
detail::rbts::bits_t B,
detail::rbts::bits_t BL>
class flex_vector_transient;
/*!
* Immutable sequential container supporting both random access,
* structural sharing and efficient concatenation and slicing.
*
* @tparam T The type of the values to be stored in the container.
* @tparam MemoryPolicy Memory management policy. See @ref
* memory_policy.
*
* @rst
*
* This container is very similar to `vector`_ but also supports
* :math:`O(log(size))` *concatenation*, *slicing* and *insertion* at
* any point. Its performance characteristics are almost identical
* until one of these operations is performed. After that,
* performance is degraded by a constant factor that usually oscilates
* in the range :math:`[1, 2)` depending on the operation and the
* amount of flexible operations that have been performed.
*
* .. tip:: A `vector`_ can be converted to a `flex_vector`_ in
* constant time without any allocation. This is so because the
* internal structure of a *vector* is a strict subset of the
* internal structure of a *flexible vector*. You can take
* advantage of this property by creating normal vectors as long as
* the flexible operations are not needed, and convert later in
* your processing pipeline once and if these are needed.
*
* @endrst
*/
template <typename T,
typename MemoryPolicy = default_memory_policy,
detail::rbts::bits_t B = default_bits,
detail::rbts::bits_t BL = detail::rbts::derive_bits_leaf<T, MemoryPolicy, B>>
class flex_vector
{
using impl_t = detail::rbts::rrbtree<T, MemoryPolicy, B, BL>;
using move_t =
std::integral_constant<bool, MemoryPolicy::use_transient_rvalues>;
public:
static constexpr auto bits = B;
static constexpr auto bits_leaf = BL;
using memory_policy = MemoryPolicy;
using value_type = T;
using reference = const T&;
using size_type = detail::rbts::size_t;
using difference_type = std::ptrdiff_t;
using const_reference = const T&;
using iterator = detail::rbts::rrbtree_iterator<T, MemoryPolicy, B, BL>;
using const_iterator = iterator;
using reverse_iterator = std::reverse_iterator<iterator>;
using transient_type = flex_vector_transient<T, MemoryPolicy, B, BL>;
/*!
* Default constructor. It creates a flex_vector of `size() == 0`.
* It does not allocate memory and its complexity is @f$ O(1) @f$.
*/
flex_vector() = default;
/*!
* Constructs a flex_vector containing the elements in `values`.
*/
flex_vector(std::initializer_list<T> values)
: impl_{impl_t::from_initializer_list(values)}
{}
/*!
* Constructs a flex_vector containing the elements in the range
* defined by the input iterator `first` and range sentinel `last`.
*/
template <typename Iter, typename Sent,
std::enable_if_t
<detail::compatible_sentinel_v<Iter, Sent>, bool> = true>
flex_vector(Iter first, Sent last)
: impl_{impl_t::from_range(first, last)}
{}
/*!
* Constructs a vector containing the element `val` repeated `n`
* times.
*/
flex_vector(size_type n, T v = {})
: impl_{impl_t::from_fill(n, v)}
{}
/*!
* Default constructor. It creates a flex_vector with the same
* contents as `v`. It does not allocate memory and is
* @f$ O(1) @f$.
*/
flex_vector(vector<T, MemoryPolicy, B, BL> v)
: impl_ { v.impl_.size, v.impl_.shift,
v.impl_.root->inc(), v.impl_.tail->inc() }
{}
/*!
* Returns an iterator pointing at the first element of the
* collection. It does not allocate memory and its complexity is
* @f$ O(1) @f$.
*/
iterator begin() const { return {impl_}; }
/*!
* Returns an iterator pointing just after the last element of the
* collection. It does not allocate and its complexity is @f$ O(1) @f$.
*/
iterator end() const { return {impl_, typename iterator::end_t{}}; }
/*!
* Returns an iterator that traverses the collection backwards,
* pointing at the first element of the reversed collection. It
* does not allocate memory and its complexity is @f$ O(1) @f$.
*/
reverse_iterator rbegin() const { return reverse_iterator{end()}; }
/*!
* Returns an iterator that traverses the collection backwards,
* pointing after the last element of the reversed collection. It
* does not allocate memory and its complexity is @f$ O(1) @f$.
*/
reverse_iterator rend() const { return reverse_iterator{begin()}; }
/*!
* Returns the number of elements in the container. It does
* not allocate memory and its complexity is @f$ O(1) @f$.
*/
size_type size() const { return impl_.size; }
/*!
* Returns `true` if there are no elements in the container. It
* does not allocate memory and its complexity is @f$ O(1) @f$.
*/
bool empty() const { return impl_.size == 0; }
/*!
* Access the last element.
*/
const T& back() const { return impl_.back(); }
/*!
* Access the first element.
*/
const T& front() const { return impl_.front(); }
/*!
* Returns a `const` reference to the element at position `index`.
* It is undefined when @f$ 0 index \geq size() @f$. It does not
* allocate memory and its complexity is *effectively* @f$ O(1)
* @f$.
*/
reference operator[] (size_type index) const
{ return impl_.get(index); }
/*!
* Returns a `const` reference to the element at position
* `index`. It throws an `std::out_of_range` exception when @f$
* index \geq size() @f$. It does not allocate memory and its
* complexity is *effectively* @f$ O(1) @f$.
*/
reference at(size_type index) const
{ return impl_.get_check(index); }
/*!
* Returns whether the vectors are equal.
*/
bool operator==(const flex_vector& other) const
{ return impl_.equals(other.impl_); }
bool operator!=(const flex_vector& other) const
{ return !(*this == other); }
/*!
* Returns a flex_vector with `value` inserted at the end. It may
* allocate memory and its complexity is *effectively* @f$ O(1) @f$.
*
* @rst
*
* **Example**
* .. literalinclude:: ../example/flex-vector/flex-vector.cpp
* :language: c++
* :dedent: 8
* :start-after: push-back/start
* :end-before: push-back/end
*
* @endrst
*/
flex_vector push_back(value_type value) const&
{ return impl_.push_back(std::move(value)); }
decltype(auto) push_back(value_type value) &&
{ return push_back_move(move_t{}, std::move(value)); }
/*!
* Returns a flex_vector with `value` inserted at the frony. It may
* allocate memory and its complexity is @f$ O(log(size)) @f$.
*
* @rst
*
* **Example**
* .. literalinclude:: ../example/flex-vector/flex-vector.cpp
* :language: c++
* :dedent: 8
* :start-after: push-front/start
* :end-before: push-front/end
*
* @endrst
*/
flex_vector push_front(value_type value) const
{ return flex_vector{}.push_back(value) + *this; }
/*!
* Returns a flex_vector containing value `value` at position `index`.
* Undefined for `index >= size()`.
* It may allocate memory and its complexity is
* *effectively* @f$ O(1) @f$.
*
* @rst
*
* **Example**
* .. literalinclude:: ../example/flex-vector/flex-vector.cpp
* :language: c++
* :dedent: 8
* :start-after: set/start
* :end-before: set/end
*
* @endrst
*/
flex_vector set(size_type index, value_type value) const&
{ return impl_.assoc(index, std::move(value)); }
decltype(auto) set(size_type index, value_type value) &&
{ return set_move(move_t{}, index, std::move(value)); }
/*!
* Returns a vector containing the result of the expression
* `fn((*this)[idx])` at position `idx`.
* Undefined for `index >= size()`.
* It may allocate memory and its complexity is
* *effectively* @f$ O(1) @f$.
*
* @rst
*
* **Example**
* .. literalinclude:: ../example/flex-vector/flex-vector.cpp
* :language: c++
* :dedent: 8
* :start-after: update/start
* :end-before: update/end
*
* @endrst
*/
template <typename FnT>
flex_vector update(size_type index, FnT&& fn) const&
{ return impl_.update(index, std::forward<FnT>(fn)); }
template <typename FnT>
decltype(auto) update(size_type index, FnT&& fn) &&
{ return update_move(move_t{}, index, std::forward<FnT>(fn)); }
/*!
* Returns a vector containing only the first `min(elems, size())`
* elements. It may allocate memory and its complexity is
* *effectively* @f$ O(1) @f$.
*
* @rst
*
* **Example**
* .. literalinclude:: ../example/flex-vector/flex-vector.cpp
* :language: c++
* :dedent: 8
* :start-after: take/start
* :end-before: take/end
*
* @endrst
*/
flex_vector take(size_type elems) const&
{ return impl_.take(elems); }
decltype(auto) take(size_type elems) &&
{ return take_move(move_t{}, elems); }
/*!
* Returns a vector without the first `min(elems, size())`
* elements. It may allocate memory and its complexity is
* *effectively* @f$ O(1) @f$.
*
* @rst
*
* **Example**
* .. literalinclude:: ../example/flex-vector/flex-vector.cpp
* :language: c++
* :dedent: 8
* :start-after: drop/start
* :end-before: drop/end
*
* @endrst
*/
flex_vector drop(size_type elems) const&
{ return impl_.drop(elems); }
decltype(auto) drop(size_type elems) &&
{ return drop_move(move_t{}, elems); }
/*!
* Concatenation operator. Returns a flex_vector with the contents
* of `l` followed by those of `r`. It may allocate memory
* and its complexity is @f$ O(log(max(size_r, size_l))) @f$
*
* @rst
*
* **Example**
* .. literalinclude:: ../example/flex-vector/flex-vector.cpp
* :language: c++
* :dedent: 8
* :start-after: concat/start
* :end-before: concat/end
*
* @endrst
*/
friend flex_vector operator+ (const flex_vector& l, const flex_vector& r)
{ return l.impl_.concat(r.impl_); }
friend decltype(auto) operator+ (flex_vector&& l, const flex_vector& r)
{ return concat_move(move_t{}, std::move(l), r); }
friend decltype(auto) operator+ (const flex_vector& l, flex_vector&& r)
{ return concat_move(move_t{}, l, std::move(r)); }
friend decltype(auto) operator+ (flex_vector&& l, flex_vector&& r)
{ return concat_move(move_t{}, std::move(l), std::move(r)); }
/*!
* Returns a flex_vector with the `value` inserted at index
* `pos`. It may allocate memory and its complexity is @f$
* O(log(size)) @f$
*
* @rst
*
* **Example**
* .. literalinclude:: ../example/flex-vector/flex-vector.cpp
* :language: c++
* :dedent: 8
* :start-after: insert/start
* :end-before: insert/end
*
* @endrst
*/
flex_vector insert(size_type pos, T value) const&
{ return take(pos).push_back(std::move(value)) + drop(pos); }
decltype(auto) insert(size_type pos, T value) &&
{
using std::move;
auto rs = drop(pos);
return std::move(*this).take(pos).push_back(
std::move(value)) + std::move(rs);
}
flex_vector insert(size_type pos, flex_vector value) const&
{ return take(pos) + std::move(value) + drop(pos); }
decltype(auto) insert(size_type pos, flex_vector value) &&
{
using std::move;
auto rs = drop(pos);
return std::move(*this).take(pos) + std::move(value) + std::move(rs);
}
/*!
* Returns a flex_vector without the element at index `pos`. It
* may allocate memory and its complexity is @f$ O(log(size)) @f$
*
* @rst
*
* **Example**
* .. literalinclude:: ../example/flex-vector/flex-vector.cpp
* :language: c++
* :dedent: 8
* :start-after: erase/start
* :end-before: erase/end
*
* @endrst
*/
flex_vector erase(size_type pos) const&
{ return take(pos) + drop(pos + 1); }
decltype(auto) erase(size_type pos) &&
{
auto rs = drop(pos + 1);
return std::move(*this).take(pos) + std::move(rs);
}
flex_vector erase(size_type pos, size_type lpos) const&
{ return lpos > pos ? take(pos) + drop(lpos) : *this; }
decltype(auto) erase(size_type pos, size_type lpos) &&
{
if (lpos > pos) {
auto rs = drop(lpos);
return std::move(*this).take(pos) + std::move(rs);
} else {
return std::move(*this);
}
}
/*!
* Returns an @a transient form of this container, an
* `immer::flex_vector_transient`.
*/
transient_type transient() const&
{ return transient_type{ impl_ }; }
transient_type transient() &&
{ return transient_type{ std::move(impl_) }; }
// Semi-private
const impl_t& impl() const { return impl_; }
#if IMMER_DEBUG_PRINT
void debug_print(std::ostream& out=std::cerr) const
{ impl_.debug_print(out); }
#endif
private:
friend transient_type;
flex_vector(impl_t impl)
: impl_(std::move(impl))
{
#if IMMER_DEBUG_PRINT
// force the compiler to generate debug_print, so we can call
// it from a debugger
[](volatile auto){}(&flex_vector::debug_print);
#endif
}
flex_vector&& push_back_move(std::true_type, value_type value)
{ impl_.push_back_mut({}, std::move(value)); return std::move(*this); }
flex_vector push_back_move(std::false_type, value_type value)
{ return impl_.push_back(std::move(value)); }
flex_vector&& set_move(std::true_type, size_type index, value_type value)
{ impl_.assoc_mut({}, index, std::move(value)); return std::move(*this); }
flex_vector set_move(std::false_type, size_type index, value_type value)
{ return impl_.assoc(index, std::move(value)); }
template <typename Fn>
flex_vector&& update_move(std::true_type, size_type index, Fn&& fn)
{ impl_.update_mut({}, index, std::forward<Fn>(fn)); return std::move(*this); }
template <typename Fn>
flex_vector update_move(std::false_type, size_type index, Fn&& fn)
{ return impl_.update(index, std::forward<Fn>(fn)); }
flex_vector&& take_move(std::true_type, size_type elems)
{ impl_.take_mut({}, elems); return std::move(*this); }
flex_vector take_move(std::false_type, size_type elems)
{ return impl_.take(elems); }
flex_vector&& drop_move(std::true_type, size_type elems)
{ impl_.drop_mut({}, elems); return std::move(*this); }
flex_vector drop_move(std::false_type, size_type elems)
{ return impl_.drop(elems); }
static flex_vector&& concat_move(std::true_type, flex_vector&& l, const flex_vector& r)
{ concat_mut_l(l.impl_, {}, r.impl_); return std::move(l); }
static flex_vector&& concat_move(std::true_type, const flex_vector& l, flex_vector&& r)
{ concat_mut_r(l.impl_, r.impl_, {}); return std::move(r); }
static flex_vector&& concat_move(std::true_type, flex_vector&& l, flex_vector&& r)
{ concat_mut_lr_l(l.impl_, {}, r.impl_, {}); return std::move(l); }
static flex_vector concat_move(std::false_type, const flex_vector& l, const flex_vector& r)
{ return l.impl_.concat(r.impl_); }
impl_t impl_ = impl_t::empty();
};
} // namespace immer