1 | /** |
2 | * Copyright 2021 Alibaba, Inc. and its affiliates. All Rights Reserved. |
3 | * |
4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
5 | * you may not use this file except in compliance with the License. |
6 | * You may obtain a copy of the License at |
7 | * |
8 | * http://www.apache.org/licenses/LICENSE-2.0 |
9 | * |
10 | * Unless required by applicable law or agreed to in writing, software |
11 | * distributed under the License is distributed on an "AS IS" BASIS, |
12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
13 | * See the License for the specific language governing permissions and |
14 | * limitations under the License. |
15 | |
16 | * \author Jiliang.ljl |
17 | * \date Mar 2021 |
18 | * \brief StringView interface |
19 | */ |
20 | |
21 | #ifndef __AILEGO_STRING_STRING_VIEW_H__ |
22 | #define __AILEGO_STRING_STRING_VIEW_H__ |
23 | |
24 | #include <string> |
25 | |
26 | namespace ailego { |
27 | |
28 | //! StringView provides a lightweight view into the string data provided by |
29 | //! a `std::string`, double-quoted string literal, character array, or even |
30 | //! another `StringView`. |
31 | //! |
32 | //! A `StringView` does *not* own the string to which it |
33 | //! points, and that data cannot be modified through the view. |
34 | class StringView { |
35 | public: |
36 | //! Default constructor |
37 | StringView() = default; |
38 | |
39 | //! Construct from c-string |
40 | StringView(const char *str) |
41 | : data_(str), size_(str != nullptr ? strlen(str) : 0) {} |
42 | |
43 | //! Construct from [str, str+s) |
44 | StringView(const char *str, size_t len) : data_(str), size_(len) {} |
45 | |
46 | //! Construct from std::string |
47 | StringView(const std::string &str) : data_(str.data()), size_(str.size()) {} |
48 | |
49 | //! Retrieve data of string |
50 | const char *data() const { |
51 | return data_; |
52 | } |
53 | |
54 | //! Retrieve size of string |
55 | size_t size() const { |
56 | return size_; |
57 | } |
58 | |
59 | //! Retrieve non-zero if it is empty |
60 | bool empty() const { |
61 | return size_ == 0; |
62 | } |
63 | |
64 | private: |
65 | const char *data_{nullptr}; |
66 | size_t size_{0}; |
67 | }; |
68 | |
69 | } // namespace ailego |
70 | |
71 | #endif // __AILEGO_STRING_STRING_VIEW_H__ |
72 | |