base/string_number_conversions.h

   1 // Copyright (c) 2011 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_STRING_NUMBER_CONVERSIONS_H_
   6 #define BASE_STRING_NUMBER_CONVERSIONS_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/base_export.h"
  12 #include "base/basictypes.h"
  13 #include "base/string16.h"
  14
  15 // ----------------------------------------------------------------------------
  16 // IMPORTANT MESSAGE FROM YOUR SPONSOR
  17 //
  18 // This file contains no "wstring" variants. New code should use string16. If
  19 // you need to make old code work, use the UTF8 version and convert. Please do
  20 // not add wstring variants.
  21 //
  22 // Please do not add "convenience" functions for converting strings to integers
  23 // that return the value and ignore success/failure. That encourages people to
  24 // write code that doesn't properly handle the error conditions.
  25 // ----------------------------------------------------------------------------
  26
  27 namespace base {
  28
  29 // Number -> string conversions ------------------------------------------------
  30
  31 BASE_EXPORT std::string IntToString(int value);
  32 BASE_EXPORT string16 IntToString16(int value);
  33
  34 BASE_EXPORT std::string UintToString(unsigned value);
  35 BASE_EXPORT string16 UintToString16(unsigned value);
  36
  37 BASE_EXPORT std::string Int64ToString(int64 value);
  38 BASE_EXPORT string16 Int64ToString16(int64 value);
  39
  40 BASE_EXPORT std::string Uint64ToString(uint64 value);
  41 BASE_EXPORT string16 Uint64ToString16(uint64 value);
  42
  43 // DoubleToString converts the double to a string format that ignores the
  44 // locale. If you want to use locale specific formatting, use ICU.
  45 BASE_EXPORT std::string DoubleToString(double value);
  46
  47 // String -> number conversions ------------------------------------------------
  48
  49 // Perform a best-effort conversion of the input string to a numeric type,
  50 // setting |*output| to the result of the conversion.  Returns true for
  51 // "perfect" conversions; returns false in the following cases:
  52 //  - Overflow/underflow.  |*output| will be set to the maximum value supported
  53 //    by the data type.
  54 //  - Trailing characters in the string after parsing the number.  |*output|
  55 //    will be set to the value of the number that was parsed.
  56 //  - Leading whitespace in the string before parsing the number. |*output| will
  57 //    be set to the value of the number that was parsed.
  58 //  - No characters parseable as a number at the beginning of the string.
  59 //    |*output| will be set to 0.
  60 //  - Empty string.  |*output| will be set to 0.
  61 BASE_EXPORT bool StringToInt(const std::string& input, int* output);
  62 BASE_EXPORT bool StringToInt(std::string::const_iterator begin,
  63                              std::string::const_iterator end,
  64                              int* output);
  65 BASE_EXPORT bool StringToInt(const char* begin, const char* end, int* output);
  66
  67 BASE_EXPORT bool StringToInt(const string16& input, int* output);
  68 BASE_EXPORT bool StringToInt(string16::const_iterator begin,
  69                              string16::const_iterator end,
  70                              int* output);
  71 BASE_EXPORT bool StringToInt(const char16* begin, const char16* end,
  72                              int* output);
  73
  74 BASE_EXPORT bool StringToInt64(const std::string& input, int64* output);
  75 BASE_EXPORT bool StringToInt64(std::string::const_iterator begin,
  76                                std::string::const_iterator end,
  77                                int64* output);
  78 BASE_EXPORT bool StringToInt64(const char* begin, const char* end,
  79                                int64* output);
  80
  81 BASE_EXPORT bool StringToInt64(const string16& input, int64* output);
  82 BASE_EXPORT bool StringToInt64(string16::const_iterator begin,
  83                                string16::const_iterator end,
  84                                int64* output);
  85 BASE_EXPORT bool StringToInt64(const char16* begin, const char16* end,
  86                                int64* output);
  87
  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-fininte 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 BASE_EXPORT bool StringToDouble(const std::string& input, double* output);
  95
  96 // Hex encoding ----------------------------------------------------------------
  97
  98 // Returns a hex string representation of a binary buffer. The returned hex
  99 // string will be in upper case. This function does not check if |size| is
 100 // within reasonable limits since it's written with trusted data in mind.  If
 101 // you suspect that the data you want to format might be large, the absolute
 102 // max size for |size| should be is
 103 //   std::numeric_limits<size_t>::max() / 2
 104 BASE_EXPORT std::string HexEncode(const void* bytes, size_t size);
 105
 106 // Best effort conversion, see StringToInt above for restrictions.
 107 BASE_EXPORT bool HexStringToInt(const std::string& input, int* output);
 108 BASE_EXPORT bool HexStringToInt(std::string::const_iterator begin,
 109                                 std::string::const_iterator end,
 110                                 int* output);
 111 BASE_EXPORT bool HexStringToInt(const char* begin, const char* end,
 112                                 int* output);
 113
 114 // Similar to the previous functions, except that output is a vector of bytes.
 115 // |*output| will contain as many bytes as were successfully parsed prior to the
 116 // error.  There is no overflow, but input.size() must be evenly divisible by 2.
 117 // Leading 0x or +/- are not allowed.
 118 BASE_EXPORT bool HexStringToBytes(const std::string& input,
 119                                   std::vector<uint8>* output);
 120
 121 }  // namespace base
 122
 123 #endif  // BASE_STRING_NUMBER_CONVERSIONS_H_
 124