1 files changed, 65 insertions, 0 deletions
diff --git a/tensorflow/compiler/xla/map_util.h b/tensorflow/compiler/xla/map_util.h
new file mode 100644
index 0000000000..51d0d5f86f
--- /dev/null
+++ b/tensorflow/compiler/xla/map_util.h
@@ -0,0 +1,65 @@
+/* Copyright 2017 The TensorFlow Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+==============================================================================*/
+
+#ifndef TENSORFLOW_COMPILER_XLA_MAP_UTIL_H_
+#define TENSORFLOW_COMPILER_XLA_MAP_UTIL_H_
+
+#include "tensorflow/core/platform/logging.h"
+
+namespace xla {
+
+// FindOrDie returns a const reference to the value associated with
+// the given key if it exists. Crashes otherwise.
+//
+// This is intended as a replacement for operator[] as an rvalue (for reading)
+// when the key is guaranteed to exist.
+template <class Collection>
+const typename Collection::value_type::second_type& FindOrDie(
+    const Collection& collection,
+    const typename Collection::value_type::first_type& key) {
+  typename Collection::const_iterator it = collection.find(key);
+  CHECK(it != collection.end()) << "Map key not found: " << key;
+  return it->second;
+}
+
+// Same as above, but returns a non-const reference.
+template <class Collection>
+typename Collection::value_type::second_type& FindOrDie(
+    Collection& collection,  // NOLINT
+    const typename Collection::value_type::first_type& key) {
+  typename Collection::iterator it = collection.find(key);
+  CHECK(it != collection.end()) << "Map key not found: " << key;
+  return it->second;
+}
+
+// Inserts the key-value pair into the collection. Dies if key was already
+// present.
+template <class Collection>
+void InsertOrDie(Collection* const collection,
+                 const typename Collection::value_type::first_type& key,
+                 const typename Collection::value_type::second_type& data) {
+  auto p = collection->insert(std::make_pair(key, data));
+  CHECK(p.second) << "duplicate key: " << key;
+}
+
+// Returns true if and only if the given collection contains the given key.
+template <class Collection, class Key>
+bool ContainsKey(const Collection& collection, const Key& key) {
+  return collection.find(key) != collection.end();
+}
+
+}  // namespace xla
+
+#endif  // TENSORFLOW_COMPILER_XLA_MAP_UTIL_H_