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/*
* Copyright (c) 2011-2014, Intel Corporation
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation and/or
* other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its contributors
* may be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <limits>
#include <sstream>
#include <string>
#include <stdint.h>
/* details namespace is here to hide implementation details to header end user. It
* is NOT intended to be used outside. */
namespace details
{
/** Helper class to limit instantiation of templates */
template<typename T>
struct ConvertionAllowed;
/* List of allowed types for conversion */
template<> struct ConvertionAllowed<bool> {};
template<> struct ConvertionAllowed<uint64_t> {};
template<> struct ConvertionAllowed<int64_t> {};
template<> struct ConvertionAllowed<uint32_t> {};
template<> struct ConvertionAllowed<int32_t> {};
template<> struct ConvertionAllowed<uint16_t> {};
template<> struct ConvertionAllowed<int16_t> {};
template<> struct ConvertionAllowed<float> {};
} // namespace details
/**
* Convert a string to a given type.
*
* This template function read the value of the type T in the given string.
* The function does not allow to have white spaces around the value to parse
* and tries to parse the whole string, which means that if some bytes were not
* read in the string, the function fails.
* Hexadecimal representation (ie numbers starting with 0x) is supported only
* for integral types conversions.
* Result may be modified, even in case of failure.
*
* @param[in] str the string to parse.
* @param[out] result reference to object where to store the result.
*
* @return true if conversion was successful, false otherwise.
*/
template<typename T>
static inline bool convertTo(const std::string &str, T &result)
{
/* Check that conversion to that type is allowed.
* If this fails, this means that this template was not intended to be used
* with this type, thus that the result is undefined. */
details::ConvertionAllowed<T>();
if (str.find_first_of(std::string("\r\n\t\v ")) != std::string::npos) {
return false;
}
/* Check for a '-' in string. If type is unsigned and a - is found, the
* parsing fails. This is made necessary because "-1" is read as 65535 for
* uint16_t, for example */
if (str.find("-") != std::string::npos
&& !std::numeric_limits<T>::is_signed) {
return false;
}
std::stringstream ss(str);
/* Sadly, the stream conversion does not handle hexadecimal format, thus
* check is done manually */
if (str.substr(0, 2) == "0x") {
if (std::numeric_limits<T>::is_integer) {
ss >> std::hex >> result;
}
else {
/* Conversion undefined for non integers */
return false;
}
} else {
ss >> result;
}
return ss.eof() && !ss.fail() && !ss.bad();
}
/**
* Specialization for int16_t of convertTo template function.
*
* This function follows the same paradigm than it's generic version.
*
* The specific implementation is made necessary because the stlport version of
* string streams is bugged and does not fail when giving overflowed values.
* This specialisation can be safely removed when stlport behaviour is fixed.
*
* @param[in] str the string to parse.
* @param[out] result reference to object where to store the result.
*
* @return true if conversion was successful, false otherwise.
*/
template<>
inline bool convertTo<int16_t>(const std::string &str, int16_t &result)
{
int64_t res;
if (!convertTo<int64_t>(str, res)) {
return false;
}
if (res > std::numeric_limits<int16_t>::max() || res < std::numeric_limits<int16_t>::min()) {
return false;
}
result = static_cast<int16_t>(res);
return true;
}
/**
* Specialization for boolean of convertTo template function.
*
* This function follows the same paradigm than it's generic version.
* This function accepts to parse boolean as "0/1" or "false/true" or
* "FALSE/TRUE".
* The specific implementation is made necessary because the behaviour of
* string streams when parsing boolean values is not sufficient to fit our
* requirements. Indeed, parsing "true" will correctly parse the value, but the
* end of stream is not reached which makes the ss.eof() fails in the generic
* implementation.
*
* @param[in] str the string to parse.
* @param[out] result reference to object where to store the result.
*
* @return true if conversion was successful, false otherwise.
*/
template<>
inline bool convertTo<bool>(const std::string &str, bool &result)
{
if (str == "0" || str == "FALSE" || str == "false") {
result = false;
return true;
}
if (str == "1" || str == "TRUE" || str == "true") {
result = true;
return true;
}
return false;
}
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