1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef BASE_STRINGS_STRING_NUMBER_CONVERSIONS_H_ 6 #define BASE_STRINGS_STRING_NUMBER_CONVERSIONS_H_ 7 8 #include <stddef.h> 9 #include <stdint.h> 10 11 #include <string> 12 #include <vector> 13 14 #include "base/base_export.h" 15 #include "base/strings/string_piece.h" 16 17 // ---------------------------------------------------------------------------- 18 // IMPORTANT MESSAGE FROM YOUR SPONSOR 19 // 20 // This file contains no "wstring" variants. New code should use string16. If 21 // you need to make old code work, use the UTF8 version and convert. Please do 22 // not add wstring variants. 23 // 24 // Please do not add "convenience" functions for converting strings to integers 25 // that return the value and ignore success/failure. That encourages people to 26 // write code that doesn't properly handle the error conditions. 27 // ---------------------------------------------------------------------------- 28 29 namespace base { 30 31 // Number -> string conversions ------------------------------------------------ 32 33 std::string IntToString(int value); 34 35 std::string UintToString(unsigned value); 36 37 std::string Int64ToString(int64_t value); 38 39 std::string Uint64ToString(uint64_t value); 40 41 std::string SizeTToString(size_t value); 42 43 // Deprecated: prefer std::to_string(double) instead. 44 // DoubleToString converts the double to a string format that ignores the 45 // locale. If you want to use locale specific formatting, use ICU. 46 std::string DoubleToString(double value); 47 48 // String -> number conversions ------------------------------------------------ 49 50 // Perform a best-effort conversion of the input string to a numeric type, 51 // setting |*output| to the result of the conversion. Returns true for 52 // "perfect" conversions; returns false in the following cases: 53 // - Overflow. |*output| will be set to the maximum value supported 54 // by the data type. 55 // - Underflow. |*output| will be set to the minimum value supported 56 // by the data type. 57 // - Trailing characters in the string after parsing the number. |*output| 58 // will be set to the value of the number that was parsed. 59 // - Leading whitespace in the string before parsing the number. |*output| will 60 // be set to the value of the number that was parsed. 61 // - No characters parseable as a number at the beginning of the string. 62 // |*output| will be set to 0. 63 // - Empty string. |*output| will be set to 0. 64 // WARNING: Will write to |output| even when returning false. 65 // Read the comments above carefully. 66 bool StringToInt(const StringPiece& input, int* output); 67 68 bool StringToUint(const StringPiece& input, unsigned* output); 69 70 bool StringToInt64(const StringPiece& input, int64_t* output); 71 72 bool StringToUint64(const StringPiece& input, uint64_t* output); 73 74 bool StringToSizeT(const StringPiece& input, size_t* output); 75 76 // Deprecated: prefer std::stod() instead. 77 // For floating-point conversions, only conversions of input strings in decimal 78 // form are defined to work. Behavior with strings representing floating-point 79 // numbers in hexadecimal, and strings representing non-finite values (such as 80 // NaN and inf) is undefined. Otherwise, these behave the same as the integral 81 // variants. This expects the input string to NOT be specific to the locale. 82 // If your input is locale specific, use ICU to read the number. 83 // WARNING: Will write to |output| even when returning false. 84 // Read the comments here and above StringToInt() carefully. 85 bool StringToDouble(const std::string& input, double* output); 86 87 // Hex encoding ---------------------------------------------------------------- 88 89 // Returns a hex string representation of a binary buffer. The returned hex 90 // string will be in upper case. This function does not check if |size| is 91 // within reasonable limits since it's written with trusted data in mind. If 92 // you suspect that the data you want to format might be large, the absolute 93 // max size for |size| should be is 94 // std::numeric_limits<size_t>::max() / 2 95 std::string HexEncode(const void* bytes, size_t size); 96 97 // Best effort conversion, see StringToInt above for restrictions. 98 // Will only successful parse hex values that will fit into |output|, i.e. 99 // -0x80000000 < |input| < 0x7FFFFFFF. 100 bool HexStringToInt(const StringPiece& input, int* output); 101 102 // Best effort conversion, see StringToInt above for restrictions. 103 // Will only successful parse hex values that will fit into |output|, i.e. 104 // 0x00000000 < |input| < 0xFFFFFFFF. 105 // The string is not required to start with 0x. 106 bool HexStringToUInt(const StringPiece& input, uint32_t* output); 107 108 // Best effort conversion, see StringToInt above for restrictions. 109 // Will only successful parse hex values that will fit into |output|, i.e. 110 // -0x8000000000000000 < |input| < 0x7FFFFFFFFFFFFFFF. 111 bool HexStringToInt64(const StringPiece& input, int64_t* output); 112 113 // Best effort conversion, see StringToInt above for restrictions. 114 // Will only successful parse hex values that will fit into |output|, i.e. 115 // 0x0000000000000000 < |input| < 0xFFFFFFFFFFFFFFFF. 116 // The string is not required to start with 0x. 117 bool HexStringToUInt64(const StringPiece& input, uint64_t* output); 118 119 // Similar to the previous functions, except that output is a vector of bytes. 120 // |*output| will contain as many bytes as were successfully parsed prior to the 121 // error. There is no overflow, but input.size() must be evenly divisible by 2. 122 // Leading 0x or +/- are not allowed. 123 bool HexStringToBytes(const std::string& input, 124 std::vector<uint8_t>* output); 125 126 } // namespace base 127 128 #endif // BASE_STRINGS_STRING_NUMBER_CONVERSIONS_H_ 129
