base/strings/string_number_conversions.h

   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 <string>
   9 #include <vector>
  10
  11 #include "base/base_export.h"
  12 #include "base/basictypes.h"
  13 #include "base/strings/string16.h"
  14 #include "base/strings/string_piece.h"
  15
  16 // ----------------------------------------------------------------------------
  17 // IMPORTANT MESSAGE FROM YOUR SPONSOR
  18 //
  19 // This file contains no "wstring" variants. New code should use string16. If
  20 // you need to make old code work, use the UTF8 version and convert. Please do
  21 // not add wstring variants.
  22 //
  23 // Please do not add "convenience" functions for converting strings to integers
  24 // that return the value and ignore success/failure. That encourages people to
  25 // write code that doesn't properly handle the error conditions.
  26 // ----------------------------------------------------------------------------
  27
  28 namespace base {
  29
  30 // Number -> string conversions ------------------------------------------------
  31
  32 BASE_EXPORT std::string IntToString(int value);
  33 BASE_EXPORT string16 IntToString16(int value);
  34
  35 BASE_EXPORT std::string UintToString(unsigned value);
  36 BASE_EXPORT string16 UintToString16(unsigned value);
  37
  38 BASE_EXPORT std::string Int64ToString(int64 value);
  39 BASE_EXPORT string16 Int64ToString16(int64 value);
  40
  41 BASE_EXPORT std::string Uint64ToString(uint64 value);
  42 BASE_EXPORT string16 Uint64ToString16(uint64 value);
  43
  44 BASE_EXPORT std::string SizeTToString(size_t value);
  45 BASE_EXPORT string16 SizeTToString16(size_t value);
  46
  47 // DoubleToString converts the double to a string format that ignores the
  48 // locale. If you want to use locale specific formatting, use ICU.
  49 BASE_EXPORT std::string DoubleToString(double value);
  50
  51 // String -> number conversions ------------------------------------------------
  52
  53 // Perform a best-effort conversion of the input string to a numeric type,
  54 // setting |*output| to the result of the conversion.  Returns true for
  55 // "perfect" conversions; returns false in the following cases:
  56 //  - Overflow. |*output| will be set to the maximum value supported
  57 //    by the data type.
  58 //  - Underflow. |*output| will be set to the minimum value supported
  59 //    by the data type.
  60 //  - Trailing characters in the string after parsing the number.  |*output|
  61 //    will be set to the value of the number that was parsed.
  62 //  - Leading whitespace in the string before parsing the number. |*output| will
  63 //    be set to the value of the number that was parsed.
  64 //  - No characters parseable as a number at the beginning of the string.
  65 //    |*output| will be set to 0.
  66 //  - Empty string.  |*output| will be set to 0.
  67 // WARNING: Will write to |output| even when returning false.
  68 //          Read the comments above carefully.
  69 BASE_EXPORT bool StringToInt(const StringPiece& input, int* output);
  70 BASE_EXPORT bool StringToInt(const StringPiece16& input, int* output);
  71
  72 BASE_EXPORT bool StringToUint(const StringPiece& input, unsigned* output);
  73 BASE_EXPORT bool StringToUint(const StringPiece16& input, unsigned* output);
  74
  75 BASE_EXPORT bool StringToInt64(const StringPiece& input, int64* output);
  76 BASE_EXPORT bool StringToInt64(const StringPiece16& input, int64* output);
  77
  78 BASE_EXPORT bool StringToUint64(const StringPiece& input, uint64* output);
  79 BASE_EXPORT bool StringToUint64(const StringPiece16& input, uint64* output);
  80
  81 BASE_EXPORT bool StringToSizeT(const StringPiece& input, size_t* output);
  82 BASE_EXPORT bool StringToSizeT(const StringPiece16& input, size_t* output);
  83
  84 // For floating-point conversions, only conversions of input strings in decimal
  85 // form are defined to work.  Behavior with strings representing floating-point
  86 // numbers in hexadecimal, and strings representing non-finite values (such as
  87 // NaN and inf) is undefined.  Otherwise, these behave the same as the integral
  88 // variants.  This expects the input string to NOT be specific to the locale.
  89 // If your input is locale specific, use ICU to read the number.
  90 // WARNING: Will write to |output| even when returning false.
  91 //          Read the comments here and above StringToInt() carefully.
  92 BASE_EXPORT bool StringToDouble(const std::string& input, double* output);
  93
  94 // Hex encoding ----------------------------------------------------------------
  95
  96 // Returns a hex string representation of a binary buffer. The returned hex
  97 // string will be in upper case. This function does not check if |size| is
  98 // within reasonable limits since it's written with trusted data in mind.  If
  99 // you suspect that the data you want to format might be large, the absolute
 100 // max size for |size| should be is
 101 //   std::numeric_limits<size_t>::max() / 2
 102 BASE_EXPORT std::string HexEncode(const void* bytes, size_t size);
 103
 104 // Best effort conversion, see StringToInt above for restrictions.
 105 // Will only successful parse hex values that will fit into |output|, i.e.
 106 // -0x80000000 < |input| < 0x7FFFFFFF.
 107 BASE_EXPORT bool HexStringToInt(const StringPiece& input, int* output);
 108
 109 // Best effort conversion, see StringToInt above for restrictions.
 110 // Will only successful parse hex values that will fit into |output|, i.e.
 111 // 0x00000000 < |input| < 0xFFFFFFFF.
 112 // The string is not required to start with 0x.
 113 BASE_EXPORT bool HexStringToUInt(const StringPiece& input, uint32* output);
 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 // -0x8000000000000000 < |input| < 0x7FFFFFFFFFFFFFFF.
 118 BASE_EXPORT bool HexStringToInt64(const StringPiece& input, int64* 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 // 0x0000000000000000 < |input| < 0xFFFFFFFFFFFFFFFF.
 123 // The string is not required to start with 0x.
 124 BASE_EXPORT bool HexStringToUInt64(const StringPiece& input, uint64* output);
 125
 126 // Similar to the previous functions, except that output is a vector of bytes.
 127 // |*output| will contain as many bytes as were successfully parsed prior to the
 128 // error.  There is no overflow, but input.size() must be evenly divisible by 2.
 129 // Leading 0x or +/- are not allowed.
 130 BASE_EXPORT bool HexStringToBytes(const std::string& input,
 131                                   std::vector<uint8>* output);
 132
 133 }  // namespace base
 134
 135 #endif  // BASE_STRINGS_STRING_NUMBER_CONVERSIONS_H_