Associative containers: add erase_if

Use a trick similar to the one we use for their ranged
constructors: support predicates that either take a
container's iterator, or that take a std::pair (for STL
compatibility).

[ChangeLog][QtCore][QMap] Added removeIf() and erase_if().

[ChangeLog][QtCore][QMultiMap] Added removeIf() and erase_if().

[ChangeLog][QtCore][QHash] Added removeIf() and erase_if().

[ChangeLog][QtCore][QMultiHash] Added removeIf() and erase_if().

Change-Id: Ie40aadf6217d7a4126a626c390d530812ebcf020
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/src/corelib/tools/qhash.h b/src/corelib/tools/qhash.h
index 8134f4402c..65ae9b75fd 100644
--- a/src/corelib/tools/qhash.h
+++ b/src/corelib/tools/qhash.h
@@ -872,6 +872,11 @@ public:
         d->erase(it);
         return true;
     }
+    template <typename Predicate>
+    qsizetype removeIf(Predicate pred)
+    {
+        return QtPrivate::associative_erase_if(*this, pred);
+    }
     T take(const Key &key)
     {
         if (isEmpty()) // prevents detaching shared null
@@ -1354,6 +1359,11 @@ public:
         d->erase(it);
         return n;
     }
+    template <typename Predicate>
+    qsizetype removeIf(Predicate pred)
+    {
+        return QtPrivate::associative_erase_if(*this, pred);
+    }
     T take(const Key &key)
     {
         if (isEmpty()) // prevents detaching shared null
@@ -1946,6 +1956,18 @@ inline size_t qHash(const QMultiHash<Key, T> &key, size_t seed = 0)
     return hash;
 }
 
+template <typename Key, typename T, typename Predicate>
+qsizetype erase_if(QHash<Key, T> &hash, Predicate pred)
+{
+    return QtPrivate::associative_erase_if(hash, pred);
+}
+
+template <typename Key, typename T, typename Predicate>
+qsizetype erase_if(QMultiHash<Key, T> &hash, Predicate pred)
+{
+    return QtPrivate::associative_erase_if(hash, pred);
+}
+
 QT_END_NAMESPACE
 
 #endif // QHASH_H