Export of internal Abseil changes

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8ebcdcac49f299156a8fd4a77501a258050960e8 by Evan Brown <ezb@google.com>:

In btree_iterator, refactor a bit and update a couple of comments.

PiperOrigin-RevId: 345491436

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421d3b9b5cf484811b9514436ce83f797e109145 by CJ Johnson <johnsoncj@google.com>:

Updates the implementation of InlinedVector to accurately express the value-initialization semantics of the default constructor

PiperOrigin-RevId: 345479151

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88f36a132b2038cb276ed1ad4d9764adb1fc78e6 by CJ Johnson <johnsoncj@google.com>:

Updates the implementation of InlinedVector to accurately express the value-initialization semantics of the default constructor

PiperOrigin-RevId: 345433064

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e55c9b4e7c578c1c4f2df65b1991041c283a97d9 by Chris Kennelly <ckennelly@google.com>:

Internal change

PiperOrigin-RevId: 345388181

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e2284c4e77ff1ebc3009e5bf520524c552226d8a by Chris Kennelly <ckennelly@google.com>:

Internal change

PiperOrigin-RevId: 345357514

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1c496a2ae07ce98578614155d63ef2ea4de5e518 by Chris Kennelly <ckennelly@google.com>:

Mark string lookup functions noexcept.

PiperOrigin-RevId: 345275012
GitOrigin-RevId: 8ebcdcac49f299156a8fd4a77501a258050960e8
Change-Id: I0ccb57d210b543270769e1378de38bf0922f8745

3 files changed, 34 insertions, 20 deletions

diff --git a/absl/container/internal/btree.h b/absl/container/internal/btree.h
index f2fc31df..dad580f5 100644
--- a/absl/container/internal/btree.h
+++ b/absl/container/internal/btree.h
@@ -910,6 +910,7 @@ struct btree_iterator {
   using key_type = typename Node::key_type;
   using size_type = typename Node::size_type;
   using params_type = typename Node::params_type;
+  using is_map_container = typename params_type::is_map_container;
 
   using node_type = Node;
   using normal_node = typename std::remove_const<Node>::type;
@@ -921,7 +922,7 @@ struct btree_iterator {
   using slot_type = typename params_type::slot_type;
 
   using iterator =
-      btree_iterator<normal_node, normal_reference, normal_pointer>;
+     btree_iterator<normal_node, normal_reference, normal_pointer>;
   using const_iterator =
       btree_iterator<const_node, const_reference, const_pointer>;
 
@@ -938,20 +939,19 @@ struct btree_iterator {
   btree_iterator(Node *n, int p) : node(n), position(p) {}
 
   // NOTE: this SFINAE allows for implicit conversions from iterator to
-  // const_iterator, but it specifically avoids defining copy constructors so
-  // that btree_iterator can be trivially copyable. This is for performance and
-  // binary size reasons.
+  // const_iterator, but it specifically avoids hiding the copy constructor so
+  // that the trivial one will be used when possible.
   template <typename N, typename R, typename P,
             absl::enable_if_t<
                 std::is_same<btree_iterator<N, R, P>, iterator>::value &&
                     std::is_same<btree_iterator, const_iterator>::value,
                 int> = 0>
-  btree_iterator(const btree_iterator<N, R, P> &other)  // NOLINT
+  btree_iterator(const btree_iterator<N, R, P> other)  // NOLINT
       : node(other.node), position(other.position) {}
 
  private:
   // This SFINAE allows explicit conversions from const_iterator to
-  // iterator, but also avoids defining a copy constructor.
+  // iterator, but also avoids hiding the copy constructor.
   // NOTE: the const_cast is safe because this constructor is only called by
   // non-const methods and the container owns the nodes.
   template <typename N, typename R, typename P,
@@ -959,7 +959,7 @@ struct btree_iterator {
                 std::is_same<btree_iterator<N, R, P>, const_iterator>::value &&
                     std::is_same<btree_iterator, iterator>::value,
                 int> = 0>
-  explicit btree_iterator(const btree_iterator<N, R, P> &other)
+  explicit btree_iterator(const btree_iterator<N, R, P> other)
       : node(const_cast<node_type *>(other.node)), position(other.position) {}
 
   // Increment/decrement the iterator.
@@ -1022,6 +1022,8 @@ struct btree_iterator {
   }
 
  private:
+  friend iterator;
+  friend const_iterator;
   template <typename Params>
   friend class btree;
   template <typename Tree>
@@ -1032,8 +1034,6 @@ struct btree_iterator {
   friend class btree_map_container;
   template <typename Tree>
   friend class btree_multiset_container;
-  template <typename N, typename R, typename P>
-  friend struct btree_iterator;
   template <typename TreeType, typename CheckerType>
   friend class base_checker;
 
@@ -1122,7 +1122,8 @@ class btree {
   using const_reference = typename Params::const_reference;
   using pointer = typename Params::pointer;
   using const_pointer = typename Params::const_pointer;
-  using iterator = btree_iterator<node_type, reference, pointer>;
+  using iterator =
+      typename btree_iterator<node_type, reference, pointer>::iterator;
   using const_iterator = typename iterator::const_iterator;
   using reverse_iterator = std::reverse_iterator<iterator>;
   using const_reverse_iterator = std::reverse_iterator<const_iterator>;
@@ -1135,7 +1136,11 @@ class btree {
  private:
   // For use in copy_or_move_values_in_order.
   const value_type &maybe_move_from_iterator(const_iterator it) { return *it; }
-  value_type &&maybe_move_from_iterator(iterator it) { return std::move(*it); }
+  value_type &&maybe_move_from_iterator(iterator it) {
+    // This is a destructive operation on the other container so it's safe for
+    // us to const_cast and move from the keys here even if it's a set.
+    return std::move(const_cast<value_type &>(*it));
+  }
 
   // Copies or moves (depending on the template parameter) the values in
   // other into this btree in their order in other. This btree must be empty
diff --git a/absl/strings/match.cc b/absl/strings/match.cc
index 8127cb0c..2d672509 100644
--- a/absl/strings/match.cc
+++ b/absl/strings/match.cc
@@ -19,19 +19,22 @@
 namespace absl {
 ABSL_NAMESPACE_BEGIN
 
-bool EqualsIgnoreCase(absl::string_view piece1, absl::string_view piece2) {
+bool EqualsIgnoreCase(absl::string_view piece1,
+                      absl::string_view piece2) noexcept {
   return (piece1.size() == piece2.size() &&
           0 == absl::strings_internal::memcasecmp(piece1.data(), piece2.data(),
                                                   piece1.size()));
   // memcasecmp uses absl::ascii_tolower().
 }
 
-bool StartsWithIgnoreCase(absl::string_view text, absl::string_view prefix) {
+bool StartsWithIgnoreCase(absl::string_view text,
+                          absl::string_view prefix) noexcept {
   return (text.size() >= prefix.size()) &&
          EqualsIgnoreCase(text.substr(0, prefix.size()), prefix);
 }
 
-bool EndsWithIgnoreCase(absl::string_view text, absl::string_view suffix) {
+bool EndsWithIgnoreCase(absl::string_view text,
+                        absl::string_view suffix) noexcept {
   return (text.size() >= suffix.size()) &&
          EqualsIgnoreCase(text.substr(text.size() - suffix.size()), suffix);
 }
diff --git a/absl/strings/match.h b/absl/strings/match.h
index 90fca98a..6c822c26 100644
--- a/absl/strings/match.h
+++ b/absl/strings/match.h
@@ -43,14 +43,16 @@ ABSL_NAMESPACE_BEGIN
 // StrContains()
 //
 // Returns whether a given string `haystack` contains the substring `needle`.
-inline bool StrContains(absl::string_view haystack, absl::string_view needle) {
+inline bool StrContains(absl::string_view haystack,
+                        absl::string_view needle) noexcept {
   return haystack.find(needle, 0) != haystack.npos;
 }
 
 // StartsWith()
 //
 // Returns whether a given string `text` begins with `prefix`.
-inline bool StartsWith(absl::string_view text, absl::string_view prefix) {
+inline bool StartsWith(absl::string_view text,
+                       absl::string_view prefix) noexcept {
   return prefix.empty() ||
          (text.size() >= prefix.size() &&
           memcmp(text.data(), prefix.data(), prefix.size()) == 0);
@@ -59,7 +61,8 @@ inline bool StartsWith(absl::string_view text, absl::string_view prefix) {
 // EndsWith()
 //
 // Returns whether a given string `text` ends with `suffix`.
-inline bool EndsWith(absl::string_view text, absl::string_view suffix) {
+inline bool EndsWith(absl::string_view text,
+                     absl::string_view suffix) noexcept {
   return suffix.empty() ||
          (text.size() >= suffix.size() &&
           memcmp(text.data() + (text.size() - suffix.size()), suffix.data(),
@@ -70,19 +73,22 @@ inline bool EndsWith(absl::string_view text, absl::string_view suffix) {
 //
 // Returns whether given ASCII strings `piece1` and `piece2` are equal, ignoring
 // case in the comparison.
-bool EqualsIgnoreCase(absl::string_view piece1, absl::string_view piece2);
+bool EqualsIgnoreCase(absl::string_view piece1,
+                      absl::string_view piece2) noexcept;
 
 // StartsWithIgnoreCase()
 //
 // Returns whether a given ASCII string `text` starts with `prefix`,
 // ignoring case in the comparison.
-bool StartsWithIgnoreCase(absl::string_view text, absl::string_view prefix);
+bool StartsWithIgnoreCase(absl::string_view text,
+                          absl::string_view prefix) noexcept;
 
 // EndsWithIgnoreCase()
 //
 // Returns whether a given ASCII string `text` ends with `suffix`, ignoring
 // case in the comparison.
-bool EndsWithIgnoreCase(absl::string_view text, absl::string_view suffix);
+bool EndsWithIgnoreCase(absl::string_view text,
+                        absl::string_view suffix) noexcept;
 
 ABSL_NAMESPACE_END
 }  // namespace absl