string_number_conversions.h

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// Copyright (c) 2012 The Chromium Authors. All rights reserved.

// Use of this source code is governed by a BSD-style license that can be

// found in the LICENSE file.

#ifndef BASE_STRINGS_STRING_NUMBER_CONVERSIONS_H_

#define BASE_STRINGS_STRING_NUMBER_CONVERSIONS_H_

#include <stddef.h>

#include <stdint.h>

#include <string>

#include <vector>

#include "base/base_export.h"

#include "base/containers/span.h"

#include "base/strings/string16.h"

#include "base/strings/string_piece.h"

#include "build/build_config.h"

// ----------------------------------------------------------------------------

// IMPORTANT MESSAGE FROM YOUR SPONSOR

//

// This file contains no "wstring" variants. New code should use string16. If

// you need to make old code work, use the UTF8 version and convert. Please do

// not add wstring variants.

//

// Please do not add "convenience" functions for converting strings to integers

// that return the value and ignore success/failure. That encourages people to

// write code that doesn't properly handle the error conditions.

//

// DO NOT use these functions in any UI unless it's NOT localized on purpose.

// Instead, use base::MessageFormatter for a complex message with numbers

// (integer, float, double) embedded or base::Format{Number,Double,Percent} to

// just format a single number/percent. Note that some languages use native

// digits instead of ASCII digits while others use a group separator or decimal

// point different from ',' and '.'. Using these functions in the UI would lead

// numbers to be formatted in a non-native way.

// ----------------------------------------------------------------------------

namespace base {

// Number -> string conversions ------------------------------------------------

// Ignores locale! see warning above.

BASE_EXPORT std::string NumberToString(int value);

BASE_EXPORT string16 NumberToString16(int value);

BASE_EXPORT std::string NumberToString(unsigned int value);

BASE_EXPORT string16 NumberToString16(unsigned int value);

BASE_EXPORT std::string NumberToString(long value);

BASE_EXPORT string16 NumberToString16(long value);

BASE_EXPORT std::string NumberToString(unsigned long value);

BASE_EXPORT string16 NumberToString16(unsigned long value);

BASE_EXPORT std::string NumberToString(long long value);

BASE_EXPORT string16 NumberToString16(long long value);

BASE_EXPORT std::string NumberToString(unsigned long long value);

BASE_EXPORT string16 NumberToString16(unsigned long long value);

BASE_EXPORT std::string NumberToString(double value);

BASE_EXPORT string16 NumberToString16(double value);

// String -> number conversions ------------------------------------------------

// Perform a best-effort conversion of the input string to a numeric type,

// setting |*output| to the result of the conversion.  Returns true for

// "perfect" conversions; returns false in the following cases:

//  - Overflow. |*output| will be set to the maximum value supported

//    by the data type.

//  - Underflow. |*output| will be set to the minimum value supported

//    by the data type.

//  - Trailing characters in the string after parsing the number.  |*output|

//    will be set to the value of the number that was parsed.

//  - Leading whitespace in the string before parsing the number. |*output| will

//    be set to the value of the number that was parsed.

//  - No characters parseable as a number at the beginning of the string.

//    |*output| will be set to 0.

//  - Empty string.  |*output| will be set to 0.

// WARNING: Will write to |output| even when returning false.

//          Read the comments above carefully.

BASE_EXPORT bool StringToInt(StringPiece input, int* output);

BASE_EXPORT bool StringToInt(StringPiece16 input, int* output);

BASE_EXPORT bool StringToUint(StringPiece input, unsigned* output);

BASE_EXPORT bool StringToUint(StringPiece16 input, unsigned* output);

BASE_EXPORT bool StringToInt64(StringPiece input, int64_t* output);

BASE_EXPORT bool StringToInt64(StringPiece16 input, int64_t* output);

BASE_EXPORT bool StringToUint64(StringPiece input, uint64_t* output);

BASE_EXPORT bool StringToUint64(StringPiece16 input, uint64_t* output);

BASE_EXPORT bool StringToSizeT(StringPiece input, size_t* output);

BASE_EXPORT bool StringToSizeT(StringPiece16 input, size_t* output);

// For floating-point conversions, only conversions of input strings in decimal

// form are defined to work.  Behavior with strings representing floating-point

// numbers in hexadecimal, and strings representing non-finite values (such as

// NaN and inf) is undefined.  Otherwise, these behave the same as the integral

// variants.  This expects the input string to NOT be specific to the locale.

// If your input is locale specific, use ICU to read the number.

// WARNING: Will write to |output| even when returning false.

//          Read the comments here and above StringToInt() carefully.

BASE_EXPORT bool StringToDouble(StringPiece input, double* output);

BASE_EXPORT bool StringToDouble(StringPiece16 input, double* output);

// Hex encoding ----------------------------------------------------------------

// Returns a hex string representation of a binary buffer. The returned hex

// string will be in upper case. This function does not check if |size| is

// within reasonable limits since it's written with trusted data in mind.  If

// you suspect that the data you want to format might be large, the absolute

// max size for |size| should be is

//   std::numeric_limits<size_t>::max() / 2

BASE_EXPORT std::string HexEncode(const void* bytes, size_t size);

BASE_EXPORT std::string HexEncode(base::span<const uint8_t> bytes);

// Best effort conversion, see StringToInt above for restrictions.

// Will only successful parse hex values that will fit into |output|, i.e.

// -0x80000000 < |input| < 0x7FFFFFFF.

BASE_EXPORT bool HexStringToInt(StringPiece input, int* output);

// Best effort conversion, see StringToInt above for restrictions.

// Will only successful parse hex values that will fit into |output|, i.e.

// 0x00000000 < |input| < 0xFFFFFFFF.

// The string is not required to start with 0x.

BASE_EXPORT bool HexStringToUInt(StringPiece input, uint32_t* output);

// Best effort conversion, see StringToInt above for restrictions.

// Will only successful parse hex values that will fit into |output|, i.e.

// -0x8000000000000000 < |input| < 0x7FFFFFFFFFFFFFFF.

BASE_EXPORT bool HexStringToInt64(StringPiece input, int64_t* output);

// Best effort conversion, see StringToInt above for restrictions.

// Will only successful parse hex values that will fit into |output|, i.e.

// 0x0000000000000000 < |input| < 0xFFFFFFFFFFFFFFFF.

// The string is not required to start with 0x.

BASE_EXPORT bool HexStringToUInt64(StringPiece input, uint64_t* output);

// Similar to the previous functions, except that output is a vector of bytes.

// |*output| will contain as many bytes as were successfully parsed prior to the

// error.  There is no overflow, but input.size() must be evenly divisible by 2.

// Leading 0x or +/- are not allowed.

BASE_EXPORT bool HexStringToBytes(StringPiece input,

                                  std::vector<uint8_t>* output);

// Same as HexStringToBytes, but for an std::string.

BASE_EXPORT bool HexStringToString(StringPiece input, std::string* output);

// Decodes the hex string |input| into a presized |output|. The output buffer

// must be sized exactly to |input.size() / 2| or decoding will fail and no

// bytes will be written to |output|. Decoding an empty input is also

// considered a failure. When decoding fails due to encountering invalid input

// characters, |output| will have been filled with the decoded bytes up until

// the failure.

BASE_EXPORT bool HexStringToSpan(StringPiece input, base::span<uint8_t> output);

}  // namespace base

#endif  // BASE_STRINGS_STRING_NUMBER_CONVERSIONS_H_