1 /* 2 * Copyright (C) 2018 The Android Open Source Project 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 17 #ifndef TC3_STD_STRING_IMPORT 18 #define TC3_STD_STRING_IMPORT 19 #include <string> 20 21 namespace libtextclassifier3 { 22 using string = std::string; 23 template <class CharT, class Traits = std::char_traits<CharT>, 24 class Allocator = std::allocator<CharT> > 25 using basic_string = std::basic_string<CharT, Traits, Allocator>; 26 } // namespace libtextclassifier3 27 #endif 28 #ifndef NLP_SAFT_COMPONENTS_COMMON_MOBILE_LITE_STRINGS_STRINGPIECE_H_ 29 #define NLP_SAFT_COMPONENTS_COMMON_MOBILE_LITE_STRINGS_STRINGPIECE_H_ 30 31 #include <stddef.h> 32 #include <string.h> 33 34 #include <ostream> 35 #include <string> 36 37 namespace libtextclassifier3 { 38 namespace mobile { 39 40 // Read-only "view" of a piece of data. Does not own the underlying data. 41 class StringPiece { 42 public: StringPiece()43 StringPiece() : StringPiece(nullptr, 0) {} 44 StringPiece(const char * str)45 StringPiece(const char *str) // NOLINT 46 : start_(str), size_(strlen(str)) {} 47 StringPiece(const char * start,size_t size)48 StringPiece(const char *start, size_t size) : start_(start), size_(size) {} 49 50 // Intentionally no "explicit" keyword: in function calls, we want strings to 51 // be converted to StringPiece implicitly. StringPiece(const string & s)52 StringPiece(const string &s) // NOLINT 53 : StringPiece(s.data(), s.size()) {} 54 StringPiece(const string & s,int offset,int len)55 StringPiece(const string &s, int offset, int len) 56 : StringPiece(s.data() + offset, len) {} 57 58 char operator[](size_t i) const { return start_[i]; } 59 60 // Returns start address of underlying data. data()61 const char *data() const { return start_; } 62 63 // Returns number of bytes of underlying data. size()64 size_t size() const { return size_; } 65 66 // Returns true if this StringPiece does not refer to any characters. empty()67 bool empty() const { return size() == 0; } 68 69 template <typename A> 70 explicit operator basic_string<char, std::char_traits<char>, A>() const { 71 if (!data()) return {}; 72 return basic_string<char, std::char_traits<char>, A>(data(), size()); 73 } 74 75 private: 76 const char *start_; // Not owned. 77 size_t size_; 78 }; 79 80 inline std::ostream &operator<<(std::ostream &out, StringPiece sp) { 81 return out.write(sp.data(), sp.size()); 82 } 83 84 } // namespace mobile 85 } // namespace nlp_saft 86 87 #endif // NLP_SAFT_COMPONENTS_COMMON_MOBILE_LITE_STRINGS_STRINGPIECE_H_ 88