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1 // Copyright 2015 The Chromium Authors. All rights reserved. | 1 // Copyright 2015 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #ifndef PDFIUM_THIRD_PARTY_BASE_STL_UTIL_H_ | 5 #ifndef PDFIUM_THIRD_PARTY_BASE_STL_UTIL_H_ |
6 #define PDFIUM_THIRD_PARTY_BASE_STL_UTIL_H_ | 6 #define PDFIUM_THIRD_PARTY_BASE_STL_UTIL_H_ |
7 | 7 |
8 #include <vector> | |
9 | |
10 namespace pdfium { | 8 namespace pdfium { |
11 | 9 |
12 // To treat a possibly-empty vector as an array, use these functions. | |
13 // If you know the array will never be empty, you can use &*v.begin() | |
14 // directly, but that is undefined behaviour if |v| is empty. | |
15 template <typename T> | |
16 inline T* vector_as_array(std::vector<T>* v) { | |
17 return v->empty() ? nullptr : &*v->begin(); | |
18 } | |
19 | |
20 template <typename T> | |
21 inline const T* vector_as_array(const std::vector<T>* v) { | |
22 return v->empty() ? nullptr : &*v->begin(); | |
23 } | |
24 | |
25 // Test to see if a set, map, hash_set or hash_map contains a particular key. | 10 // Test to see if a set, map, hash_set or hash_map contains a particular key. |
26 // Returns true if the key is in the collection. | 11 // Returns true if the key is in the collection. |
27 template <typename Collection, typename Key> | 12 template <typename Collection, typename Key> |
28 bool ContainsKey(const Collection& collection, const Key& key) { | 13 bool ContainsKey(const Collection& collection, const Key& key) { |
29 return collection.find(key) != collection.end(); | 14 return collection.find(key) != collection.end(); |
30 } | 15 } |
31 | 16 |
32 // Test to see if a collection like a vector contains a particular value. | 17 // Test to see if a collection like a vector contains a particular value. |
33 // Returns true if the value is in the collection. | 18 // Returns true if the value is in the collection. |
34 template <typename Collection, typename Value> | 19 template <typename Collection, typename Value> |
35 bool ContainsValue(const Collection& collection, const Value& value) { | 20 bool ContainsValue(const Collection& collection, const Value& value) { |
36 return std::find(collection.begin(), collection.end(), value) != | 21 return std::find(collection.begin(), collection.end(), value) != |
37 collection.end(); | 22 collection.end(); |
38 } | 23 } |
39 | 24 |
40 } // namespace pdfium | 25 } // namespace pdfium |
41 | 26 |
42 #endif // PDFIUM_THIRD_PARTY_BASE_STL_UTIL_H_ | 27 #endif // PDFIUM_THIRD_PARTY_BASE_STL_UTIL_H_ |
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