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 NLP_SAFT_COMPONENTS_COMMON_MOBILE_LITE_STRINGS_STR_CAT_H_ 18 #define NLP_SAFT_COMPONENTS_COMMON_MOBILE_LITE_STRINGS_STR_CAT_H_ 19 20 // Less efficient but more compact versions of several absl string utils. 21 // 22 // "More compact" means "pulls in fewer code dependencies". That's useful if 23 // one tries to minimize the code size. 24 // 25 // Note: the name and the signature of the functions from this header were 26 // chosen to minimize the effort of converting code that uses absl::LiteStrCat & 27 // co to our more compact functions. 28 29 #include <string> 30 31 #ifdef COMPILER_MSVC 32 #include <sstream> 33 #endif // COMPILER_MSVC 34 35 namespace libtextclassifier3 { 36 namespace mobile { 37 38 // Less efficient but more compact version of absl::LiteStrCat(). 39 // 40 // Given a value v (see supported types below) LiteStrCat(v) returns a new 41 // string that contains the representation of v. For examples, see 42 // str-cat_test.cc. 43 template <typename T> 44 inline string LiteStrCat(T v) { 45 #ifdef COMPILER_MSVC 46 std::stringstream stream; 47 stream << input; 48 return stream.str(); 49 #else 50 return std::to_string(v); 51 #endif 52 } 53 54 template <> 55 inline string LiteStrCat(const char *v) { 56 return string(v); 57 } 58 59 // TODO(salcianu): use a reference type (const string &). For some reason, I 60 // couldn't get that to work on a first try. 61 template <> 62 inline string LiteStrCat(string v) { 63 return v; 64 } 65 66 template <> 67 inline string LiteStrCat(char v) { 68 return string(1, v); 69 } 70 71 // Less efficient but more compact version of absl::LiteStrAppend(). 72 template <typename T> 73 inline void LiteStrAppend(string *dest, T v) { 74 dest->append(LiteStrCat(v)); // NOLINT 75 } 76 77 template <typename T1, typename T2> 78 inline void LiteStrAppend(string *dest, T1 v1, T2 v2) { 79 dest->append(LiteStrCat(v1)); // NOLINT 80 dest->append(LiteStrCat(v2)); // NOLINT 81 } 82 83 template <typename T1, typename T2, typename T3> 84 inline void LiteStrAppend(string *dest, T1 v1, T2 v2, T3 v3) { 85 LiteStrAppend(dest, v1, v2); 86 dest->append(LiteStrCat(v3)); // NOLINT 87 } 88 89 template <typename T1, typename T2, typename T3, typename T4> 90 inline void LiteStrAppend(string *dest, T1 v1, T2 v2, T3 v3, T4 v4) { 91 LiteStrAppend(dest, v1, v2, v3); 92 dest->append(LiteStrCat(v4)); // NOLINT 93 } 94 95 } // namespace mobile 96 } // namespace nlp_saft 97 98 #endif // NLP_SAFT_COMPONENTS_COMMON_MOBILE_LITE_STRINGS_STR_CAT_H_ 99
