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/containers/span.h" 16 #include "base/strings/string16.h" 17 #include "base/strings/string_piece.h" 18 #include "build/build_config.h" 19 20 // ---------------------------------------------------------------------------- 21 // IMPORTANT MESSAGE FROM YOUR SPONSOR 22 // 23 // This file contains no "wstring" variants. New code should use string16. If 24 // you need to make old code work, use the UTF8 version and convert. Please do 25 // not add wstring variants. 26 // 27 // Please do not add "convenience" functions for converting strings to integers 28 // that return the value and ignore success/failure. That encourages people to 29 // write code that doesn't properly handle the error conditions. 30 // 31 // DO NOT use these functions in any UI unless it's NOT localized on purpose. 32 // Instead, use base::MessageFormatter for a complex message with numbers 33 // (integer, float, double) embedded or base::Format{Number,Double,Percent} to 34 // just format a single number/percent. Note that some languages use native 35 // digits instead of ASCII digits while others use a group separator or decimal 36 // point different from ',' and '.'. Using these functions in the UI would lead 37 // numbers to be formatted in a non-native way. 38 // ---------------------------------------------------------------------------- 39 40 namespace base { 41 42 // Number -> string conversions ------------------------------------------------ 43 44 // Ignores locale! see warning above. 45 BASE_EXPORT std::string NumberToString(int value); 46 BASE_EXPORT string16 NumberToString16(int value); 47 BASE_EXPORT std::string NumberToString(unsigned int value); 48 BASE_EXPORT string16 NumberToString16(unsigned int value); 49 BASE_EXPORT std::string NumberToString(long value); 50 BASE_EXPORT string16 NumberToString16(long value); 51 BASE_EXPORT std::string NumberToString(unsigned long value); 52 BASE_EXPORT string16 NumberToString16(unsigned long value); 53 BASE_EXPORT std::string NumberToString(long long value); 54 BASE_EXPORT string16 NumberToString16(long long value); 55 BASE_EXPORT std::string NumberToString(unsigned long long value); 56 BASE_EXPORT string16 NumberToString16(unsigned long long value); 57 BASE_EXPORT std::string NumberToString(double value); 58 BASE_EXPORT string16 NumberToString16(double value); 59 60 // String -> number conversions ------------------------------------------------ 61 62 // Perform a best-effort conversion of the input string to a numeric type, 63 // setting |*output| to the result of the conversion. Returns true for 64 // "perfect" conversions; returns false in the following cases: 65 // - Overflow. |*output| will be set to the maximum value supported 66 // by the data type. 67 // - Underflow. |*output| will be set to the minimum value supported 68 // by the data type. 69 // - Trailing characters in the string after parsing the number. |*output| 70 // will be set to the value of the number that was parsed. 71 // - Leading whitespace in the string before parsing the number. |*output| will 72 // be set to the value of the number that was parsed. 73 // - No characters parseable as a number at the beginning of the string. 74 // |*output| will be set to 0. 75 // - Empty string. |*output| will be set to 0. 76 // WARNING: Will write to |output| even when returning false. 77 // Read the comments above carefully. 78 BASE_EXPORT bool StringToInt(StringPiece input, int* output); 79 BASE_EXPORT bool StringToInt(StringPiece16 input, int* output); 80 81 BASE_EXPORT bool StringToUint(StringPiece input, unsigned* output); 82 BASE_EXPORT bool StringToUint(StringPiece16 input, unsigned* output); 83 84 BASE_EXPORT bool StringToInt64(StringPiece input, int64_t* output); 85 BASE_EXPORT bool StringToInt64(StringPiece16 input, int64_t* output); 86 87 BASE_EXPORT bool StringToUint64(StringPiece input, uint64_t* output); 88 BASE_EXPORT bool StringToUint64(StringPiece16 input, uint64_t* output); 89 90 BASE_EXPORT bool StringToSizeT(StringPiece input, size_t* output); 91 BASE_EXPORT bool StringToSizeT(StringPiece16 input, size_t* output); 92 93 // For floating-point conversions, only conversions of input strings in decimal 94 // form are defined to work. Behavior with strings representing floating-point 95 // numbers in hexadecimal, and strings representing non-finite values (such as 96 // NaN and inf) is undefined. Otherwise, these behave the same as the integral 97 // variants. This expects the input string to NOT be specific to the locale. 98 // If your input is locale specific, use ICU to read the number. 99 // WARNING: Will write to |output| even when returning false. 100 // Read the comments here and above StringToInt() carefully. 101 BASE_EXPORT bool StringToDouble(StringPiece input, double* output); 102 BASE_EXPORT bool StringToDouble(StringPiece16 input, double* output); 103 104 // Hex encoding ---------------------------------------------------------------- 105 106 // Returns a hex string representation of a binary buffer. The returned hex 107 // string will be in upper case. This function does not check if |size| is 108 // within reasonable limits since it's written with trusted data in mind. If 109 // you suspect that the data you want to format might be large, the absolute 110 // max size for |size| should be is 111 // std::numeric_limits<size_t>::max() / 2 112 BASE_EXPORT std::string HexEncode(const void* bytes, size_t size); 113 BASE_EXPORT std::string HexEncode(base::span<const uint8_t> bytes); 114 115 // Best effort conversion, see StringToInt above for restrictions. 116 // Will only successful parse hex values that will fit into |output|, i.e. 117 // -0x80000000 < |input| < 0x7FFFFFFF. 118 BASE_EXPORT bool HexStringToInt(StringPiece input, int* output); 119 120 // Best effort conversion, see StringToInt above for restrictions. 121 // Will only successful parse hex values that will fit into |output|, i.e. 122 // 0x00000000 < |input| < 0xFFFFFFFF. 123 // The string is not required to start with 0x. 124 BASE_EXPORT bool HexStringToUInt(StringPiece input, uint32_t* output); 125 126 // Best effort conversion, see StringToInt above for restrictions. 127 // Will only successful parse hex values that will fit into |output|, i.e. 128 // -0x8000000000000000 < |input| < 0x7FFFFFFFFFFFFFFF. 129 BASE_EXPORT bool HexStringToInt64(StringPiece input, int64_t* output); 130 131 // Best effort conversion, see StringToInt above for restrictions. 132 // Will only successful parse hex values that will fit into |output|, i.e. 133 // 0x0000000000000000 < |input| < 0xFFFFFFFFFFFFFFFF. 134 // The string is not required to start with 0x. 135 BASE_EXPORT bool HexStringToUInt64(StringPiece input, uint64_t* output); 136 137 // Similar to the previous functions, except that output is a vector of bytes. 138 // |*output| will contain as many bytes as were successfully parsed prior to the 139 // error. There is no overflow, but input.size() must be evenly divisible by 2. 140 // Leading 0x or +/- are not allowed. 141 BASE_EXPORT bool HexStringToBytes(StringPiece input, 142 std::vector<uint8_t>* output); 143 144 // Same as HexStringToBytes, but for an std::string. 145 BASE_EXPORT bool HexStringToString(StringPiece input, std::string* output); 146 147 // Decodes the hex string |input| into a presized |output|. The output buffer 148 // must be sized exactly to |input.size() / 2| or decoding will fail and no 149 // bytes will be written to |output|. Decoding an empty input is also 150 // considered a failure. When decoding fails due to encountering invalid input 151 // characters, |output| will have been filled with the decoded bytes up until 152 // the failure. 153 BASE_EXPORT bool HexStringToSpan(StringPiece input, base::span<uint8_t> output); 154 155 } // namespace base 156 157 #endif // BASE_STRINGS_STRING_NUMBER_CONVERSIONS_H_ 158