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      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/string16.h"
     16 #include "base/strings/string_piece.h"
     17 
     18 // ----------------------------------------------------------------------------
     19 // IMPORTANT MESSAGE FROM YOUR SPONSOR
     20 //
     21 // This file contains no "wstring" variants. New code should use string16. If
     22 // you need to make old code work, use the UTF8 version and convert. Please do
     23 // not add wstring variants.
     24 //
     25 // Please do not add "convenience" functions for converting strings to integers
     26 // that return the value and ignore success/failure. That encourages people to
     27 // write code that doesn't properly handle the error conditions.
     28 // ----------------------------------------------------------------------------
     29 
     30 namespace base {
     31 
     32 // Number -> string conversions ------------------------------------------------
     33 
     34 BASE_EXPORT std::string IntToString(int value);
     35 BASE_EXPORT string16 IntToString16(int value);
     36 
     37 BASE_EXPORT std::string UintToString(unsigned value);
     38 BASE_EXPORT string16 UintToString16(unsigned value);
     39 
     40 BASE_EXPORT std::string Int64ToString(int64_t value);
     41 BASE_EXPORT string16 Int64ToString16(int64_t value);
     42 
     43 BASE_EXPORT std::string Uint64ToString(uint64_t value);
     44 BASE_EXPORT string16 Uint64ToString16(uint64_t value);
     45 
     46 BASE_EXPORT std::string SizeTToString(size_t value);
     47 BASE_EXPORT string16 SizeTToString16(size_t value);
     48 
     49 // Deprecated: prefer std::to_string(double) instead.
     50 // DoubleToString converts the double to a string format that ignores the
     51 // locale. If you want to use locale specific formatting, use ICU.
     52 BASE_EXPORT std::string DoubleToString(double value);
     53 
     54 // String -> number conversions ------------------------------------------------
     55 
     56 // Perform a best-effort conversion of the input string to a numeric type,
     57 // setting |*output| to the result of the conversion.  Returns true for
     58 // "perfect" conversions; returns false in the following cases:
     59 //  - Overflow. |*output| will be set to the maximum value supported
     60 //    by the data type.
     61 //  - Underflow. |*output| will be set to the minimum value supported
     62 //    by the data type.
     63 //  - Trailing characters in the string after parsing the number.  |*output|
     64 //    will be set to the value of the number that was parsed.
     65 //  - Leading whitespace in the string before parsing the number. |*output| will
     66 //    be set to the value of the number that was parsed.
     67 //  - No characters parseable as a number at the beginning of the string.
     68 //    |*output| will be set to 0.
     69 //  - Empty string.  |*output| will be set to 0.
     70 // WARNING: Will write to |output| even when returning false.
     71 //          Read the comments above carefully.
     72 BASE_EXPORT bool StringToInt(const StringPiece& input, int* output);
     73 BASE_EXPORT bool StringToInt(const StringPiece16& input, int* output);
     74 
     75 BASE_EXPORT bool StringToUint(const StringPiece& input, unsigned* output);
     76 BASE_EXPORT bool StringToUint(const StringPiece16& input, unsigned* output);
     77 
     78 BASE_EXPORT bool StringToInt64(const StringPiece& input, int64_t* output);
     79 BASE_EXPORT bool StringToInt64(const StringPiece16& input, int64_t* output);
     80 
     81 BASE_EXPORT bool StringToUint64(const StringPiece& input, uint64_t* output);
     82 BASE_EXPORT bool StringToUint64(const StringPiece16& input, uint64_t* output);
     83 
     84 BASE_EXPORT bool StringToSizeT(const StringPiece& input, size_t* output);
     85 BASE_EXPORT bool StringToSizeT(const StringPiece16& input, size_t* output);
     86 
     87 // Deprecated: prefer std::stod() instead.
     88 // For floating-point conversions, only conversions of input strings in decimal
     89 // form are defined to work.  Behavior with strings representing floating-point
     90 // numbers in hexadecimal, and strings representing non-finite values (such as
     91 // NaN and inf) is undefined.  Otherwise, these behave the same as the integral
     92 // variants.  This expects the input string to NOT be specific to the locale.
     93 // If your input is locale specific, use ICU to read the number.
     94 // WARNING: Will write to |output| even when returning false.
     95 //          Read the comments here and above StringToInt() carefully.
     96 BASE_EXPORT bool StringToDouble(const std::string& input, double* output);
     97 
     98 // Hex encoding ----------------------------------------------------------------
     99 
    100 // Returns a hex string representation of a binary buffer. The returned hex
    101 // string will be in upper case. This function does not check if |size| is
    102 // within reasonable limits since it's written with trusted data in mind.  If
    103 // you suspect that the data you want to format might be large, the absolute
    104 // max size for |size| should be is
    105 //   std::numeric_limits<size_t>::max() / 2
    106 BASE_EXPORT std::string HexEncode(const void* bytes, size_t size);
    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 // -0x80000000 < |input| < 0x7FFFFFFF.
    111 BASE_EXPORT bool HexStringToInt(const StringPiece& input, int* 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 // 0x00000000 < |input| < 0xFFFFFFFF.
    116 // The string is not required to start with 0x.
    117 BASE_EXPORT bool HexStringToUInt(const StringPiece& input, uint32_t* output);
    118 
    119 // Best effort conversion, see StringToInt above for restrictions.
    120 // Will only successful parse hex values that will fit into |output|, i.e.
    121 // -0x8000000000000000 < |input| < 0x7FFFFFFFFFFFFFFF.
    122 BASE_EXPORT bool HexStringToInt64(const StringPiece& input, int64_t* output);
    123 
    124 // Best effort conversion, see StringToInt above for restrictions.
    125 // Will only successful parse hex values that will fit into |output|, i.e.
    126 // 0x0000000000000000 < |input| < 0xFFFFFFFFFFFFFFFF.
    127 // The string is not required to start with 0x.
    128 BASE_EXPORT bool HexStringToUInt64(const StringPiece& input, uint64_t* output);
    129 
    130 // Similar to the previous functions, except that output is a vector of bytes.
    131 // |*output| will contain as many bytes as were successfully parsed prior to the
    132 // error.  There is no overflow, but input.size() must be evenly divisible by 2.
    133 // Leading 0x or +/- are not allowed.
    134 BASE_EXPORT bool HexStringToBytes(const std::string& input,
    135                                   std::vector<uint8_t>* output);
    136 
    137 }  // namespace base
    138 
    139 #endif  // BASE_STRINGS_STRING_NUMBER_CONVERSIONS_H_
    140