from_string.h

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2019, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */

#pragma once

#include <sstream>
#include <string>

namespace mrpt
{
namespace internal
{
inline std::istringstream& get_istringstream()
{
    static thread_local std::istringstream stream;
    stream.str("");
    return stream;
}
}  // namespace internal

/** Converts from string to any data type that supports reading (>>) from a text
 * stream. In case of error, the given default value is returned, or an
 * exception raised. \ingroup mrpt_core_grp
 */
template <typename T>
inline T from_string(
    const std::string& s, const T& defValue = T{}, bool throw_on_error = true)
{
    auto& iss(internal::get_istringstream());
    iss.str(s);
    T result = defValue;
    if (!(iss >> result))
    {
        if (throw_on_error)
            throw std::runtime_error(
                std::string("[from_string()] Cannot parse string: ") + s);
    }
    return result;
}

}  // namespace mrpt