string_number_conversions.h revision ddb351dbec246cf1fab5ec20d2d5520909041de1 
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_api.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
27namespace base {
28
29// Number -> string conversions ------------------------------------------------
30
31BASE_API std::string IntToString(int value);
32BASE_API string16 IntToString16(int value);
33
34BASE_API std::string UintToString(unsigned value);
35BASE_API string16 UintToString16(unsigned value);
36
37BASE_API std::string Int64ToString(int64 value);
38BASE_API string16 Int64ToString16(int64 value);
39
40BASE_API std::string Uint64ToString(uint64 value);
41BASE_API 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.
45BASE_API 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.
61BASE_API bool StringToInt(const std::string& input, int* output);
62BASE_API bool StringToInt(std::string::const_iterator begin,
63                          std::string::const_iterator end,
64                          int* output);
65BASE_API bool StringToInt(const char* begin, const char* end, int* output);
66
67BASE_API bool StringToInt(const string16& input, int* output);
68BASE_API bool StringToInt(string16::const_iterator begin,
69                          string16::const_iterator end,
70                          int* output);
71BASE_API bool StringToInt(const char16* begin, const char16* end, int* output);
72
73BASE_API bool StringToInt64(const std::string& input, int64* output);
74BASE_API bool StringToInt64(std::string::const_iterator begin,
75                            std::string::const_iterator end,
76                            int64* output);
77BASE_API bool StringToInt64(const char* begin, const char* end, int64* output);
78
79BASE_API bool StringToInt64(const string16& input, int64* output);
80BASE_API bool StringToInt64(string16::const_iterator begin,
81                            string16::const_iterator end,
82                            int64* output);
83BASE_API bool StringToInt64(const char16* begin, const char16* end,
84                            int64* output);
85
86// For floating-point conversions, only conversions of input strings in decimal
87// form are defined to work.  Behavior with strings representing floating-point
88// numbers in hexadecimal, and strings representing non-fininte values (such as
89// NaN and inf) is undefined.  Otherwise, these behave the same as the integral
90// variants.  This expects the input string to NOT be specific to the locale.
91// If your input is locale specific, use ICU to read the number.
92BASE_API 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
102BASE_API std::string HexEncode(const void* bytes, size_t size);
103
104// Best effort conversion, see StringToInt above for restrictions.
105BASE_API bool HexStringToInt(const std::string& input, int* output);
106BASE_API bool HexStringToInt(std::string::const_iterator begin,
107                             std::string::const_iterator end,
108                             int* output);
109BASE_API bool HexStringToInt(const char* begin, const char* end, int* output);
110
111// Similar to the previous functions, except that output is a vector of bytes.
112// |*output| will contain as many bytes as were successfully parsed prior to the
113// error.  There is no overflow, but input.size() must be evenly divisible by 2.
114// Leading 0x or +/- are not allowed.
115BASE_API bool HexStringToBytes(const std::string& input,
116                               std::vector<uint8>* output);
117
118}  // namespace base
119
120#endif  // BASE_STRING_NUMBER_CONVERSIONS_H_
121
122