merge(3p/immer): Subtree merge at 'ad3e3556d' as 'third_party/immer' r/1299

Change-Id: I9636a41ad44b4218293833fd3e9456d9b07c731b

1 files changed, 127 insertions, 0 deletions

diff --git a/third_party/immer/immer/detail/arrays/node.hpp b/third_party/immer/immer/detail/arrays/node.hpp
new file mode 100644
index 000000000000..f96a63a9f4af
--- /dev/null
+++ b/third_party/immer/immer/detail/arrays/node.hpp
@@ -0,0 +1,127 @@
+//
+// 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/combine_standard_layout.hpp>
+#include <immer/detail/type_traits.hpp>
+#include <immer/detail/util.hpp>
+
+#include <limits>
+
+namespace immer {
+namespace detail {
+namespace arrays {
+
+template <typename T, typename MemoryPolicy>
+struct node
+{
+    using memory     = MemoryPolicy;
+    using heap       = typename MemoryPolicy::heap::type;
+    using transience = typename memory::transience_t;
+    using refs_t     = typename memory::refcount;
+    using ownee_t    = typename transience::ownee;
+    using node_t     = node;
+    using edit_t     = typename transience::edit;
+
+    struct data_t
+    {
+        aligned_storage_for<T> buffer;
+    };
+
+    using impl_t = combine_standard_layout_t<data_t, refs_t, ownee_t>;
+
+    impl_t impl;
+
+    constexpr static std::size_t sizeof_n(size_t count)
+    {
+        return immer_offsetof(impl_t, d.buffer) +
+               sizeof(T) * (count == 0 ? 1 : count);
+    }
+
+    refs_t& refs() const { return auto_const_cast(get<refs_t>(impl)); }
+
+    const ownee_t& ownee() const { return get<ownee_t>(impl); }
+    ownee_t& ownee() { return get<ownee_t>(impl); }
+
+    const T* data() const { return reinterpret_cast<const T*>(&impl.d.buffer); }
+    T* data() { return reinterpret_cast<T*>(&impl.d.buffer); }
+
+    bool can_mutate(edit_t e) const
+    {
+        return refs().unique() || ownee().can_mutate(e);
+    }
+
+    static void delete_n(node_t* p, size_t sz, size_t cap)
+    {
+        destroy_n(p->data(), sz);
+        heap::deallocate(sizeof_n(cap), p);
+    }
+
+    static node_t* make_n(size_t n)
+    {
+        return new (heap::allocate(sizeof_n(n))) node_t{};
+    }
+
+    static node_t* make_e(edit_t e, size_t n)
+    {
+        auto p     = make_n(n);
+        p->ownee() = e;
+        return p;
+    }
+
+    static node_t* fill_n(size_t n, T v)
+    {
+        auto p = make_n(n);
+        try {
+            std::uninitialized_fill_n(p->data(), n, v);
+            return p;
+        } catch (...) {
+            heap::deallocate(sizeof_n(n), p);
+            throw;
+        }
+    }
+
+    template <typename Iter,
+              typename Sent,
+              std::enable_if_t<detail::compatible_sentinel_v<Iter, Sent>,
+                               bool> = true>
+    static node_t* copy_n(size_t n, Iter first, Sent last)
+    {
+        auto p = make_n(n);
+        try {
+            uninitialized_copy(first, last, p->data());
+            return p;
+        } catch (...) {
+            heap::deallocate(sizeof_n(n), p);
+            throw;
+        }
+    }
+
+    static node_t* copy_n(size_t n, node_t* p, size_t count)
+    {
+        return copy_n(n, p->data(), p->data() + count);
+    }
+
+    template <typename Iter>
+    static node_t* copy_e(edit_t e, size_t n, Iter first, Iter last)
+    {
+        auto p     = copy_n(n, first, last);
+        p->ownee() = e;
+        return p;
+    }
+
+    static node_t* copy_e(edit_t e, size_t n, node_t* p, size_t count)
+    {
+        return copy_e(e, n, p->data(), p->data() + count);
+    }
+};
+
+} // namespace arrays
+} // namespace detail
+} // namespace immer