Export of internal Abseil changes

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e2a571b818faaec4185426a8cf71fd2970674423 by Matt Kulukundis <kfm@google.com>:

Fix missed use of old RTTI macro

PiperOrigin-RevId: 413239579

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e3c15a3fe0a4e44d6e08d69ad912b2245a403bd6 by Derek Mauro <dmauro@google.com>:

Makes erase_if return the number of erased elements for compatibility
with C++20

https://en.cppreference.com/w/cpp/container/unordered_map/erase_if

This may technically be an API break, but no actual breaks were found
in Google code. Fixes to open source code should be trivial.

Closes #1065

PiperOrigin-RevId: 413204392

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c1fb1ddbc2def3f3d177e5b80b9934bdbb7b16fc by Matt Kulukundis <kfm@google.com>:

Consolidate to a single HAS_RTTI macro

PiperOrigin-RevId: 413169336
GitOrigin-RevId: e2a571b818faaec4185426a8cf71fd2970674423
Change-Id: I74b78ebd5fc172e3f5fcbd13a58cf53f7b250ae9

1 files changed, 10 insertions, 2 deletions

diff --git a/absl/container/btree_map.h b/absl/container/btree_map.h
index 4eafe062..797b949f 100644
--- a/absl/container/btree_map.h
+++ b/absl/container/btree_map.h
@@ -478,8 +478,11 @@ void swap(btree_map<K, V, C, A> &x, btree_map<K, V, C, A> &y) {
 // absl::erase_if(absl::btree_map<>, Pred)
 //
 // Erases all elements that satisfy the predicate pred from the container.
+// Returns the number of erased elements.
 template <typename K, typename V, typename C, typename A, typename Pred>
-void erase_if(btree_map<K, V, C, A> &map, Pred pred) {
+typename btree_map<K, V, C, A>::size_type erase_if(
+    btree_map<K, V, C, A> &map, Pred pred) {
+  const auto initial_size = map.size();
   for (auto it = map.begin(); it != map.end();) {
     if (pred(*it)) {
       it = map.erase(it);
@@ -487,6 +490,7 @@ void erase_if(btree_map<K, V, C, A> &map, Pred pred) {
       ++it;
     }
   }
+  return initial_size - map.size();
 }
 
 // absl::btree_multimap
@@ -809,8 +813,11 @@ void swap(btree_multimap<K, V, C, A> &x, btree_multimap<K, V, C, A> &y) {
 // absl::erase_if(absl::btree_multimap<>, Pred)
 //
 // Erases all elements that satisfy the predicate pred from the container.
+// Returns the number of erased elements.
 template <typename K, typename V, typename C, typename A, typename Pred>
-void erase_if(btree_multimap<K, V, C, A> &map, Pred pred) {
+typename btree_multimap<K, V, C, A>::size_type erase_if(
+    btree_multimap<K, V, C, A> &map, Pred pred) {
+  const auto initial_size = map.size();
   for (auto it = map.begin(); it != map.end();) {
     if (pred(*it)) {
       it = map.erase(it);
@@ -818,6 +825,7 @@ void erase_if(btree_multimap<K, V, C, A> &map, Pred pred) {
       ++it;
     }
   }
+  return initial_size - map.size();
 }
 
 namespace container_internal {