string_cast.h

Go to the documentation of this file.

/** @file
 *  @author Bram de Greve (bramz@users.sourceforge.net)
 *  @author Tom De Muer (tomdemuer@users.sourceforge.net)
 *
 *  *** BEGIN LICENSE INFORMATION ***
 *  
 *  The contents of this file are subject to the Common Public Attribution License 
 *  Version 1.0 (the "License"); you may not use this file except in compliance with 
 *  the License. You may obtain a copy of the License at 
 *  http://lass.sourceforge.net/cpal-license. The License is based on the 
 *  Mozilla Public License Version 1.1 but Sections 14 and 15 have been added to cover 
 *  use of software over a computer network and provide for limited attribution for 
 *  the Original Developer. In addition, Exhibit A has been modified to be consistent 
 *  with Exhibit B.
 *  
 *  Software distributed under the License is distributed on an "AS IS" basis, WITHOUT 
 *  WARRANTY OF ANY KIND, either express or implied. See the License for the specific 
 *  language governing rights and limitations under the License.
 *  
 *  The Original Code is LASS - Library of Assembled Shared Sources.
 *  
 *  The Initial Developer of the Original Code is Bram de Greve and Tom De Muer.
 *  The Original Developer is the Initial Developer.
 *  
 *  All portions of the code written by the Initial Developer are:
 *  Copyright (C) 2004-2007 the Initial Developer.
 *  All Rights Reserved.
 *  
 *  Contributor(s):
 *
 *  Alternatively, the contents of this file may be used under the terms of the 
 *  GNU General Public License Version 2 or later (the GPL), in which case the 
 *  provisions of GPL are applicable instead of those above.  If you wish to allow use
 *  of your version of this file only under the terms of the GPL and not to allow 
 *  others to use your version of this file under the CPAL, indicate your decision by 
 *  deleting the provisions above and replace them with the notice and other 
 *  provisions required by the GPL License. If you do not delete the provisions above,
 *  a recipient may use your version of this file under either the CPAL or the GPL.
 *  
 *  *** END LICENSE INFORMATION ***
 */

#ifndef LASS_GUARDIAN_OF_INCLUSION_UTIL_STRING_CAST_H
#define LASS_GUARDIAN_OF_INCLUSION_UTIL_STRING_CAST_H

#include "util_common.h"
#include "../stde/extended_io.h"
#include <limits>

namespace lass
{
namespace util
{

class BadStringCast: public Exception
{
public:
    BadStringCast(const std::string& msg, const std::string& loc): Exception(msg, loc) {}
private:
    LASS_UTIL_EXCEPTION_PRIVATE_IMPL(BadStringCast)
};

namespace impl
{

class StringCast
{
public:
    StringCast(const std::string& in):
        buffer_(in)
    {       
    }
    ~StringCast() {}
    template <typename In> StringCast(const In& in)
    {
        typedef std::numeric_limits<typename CallTraits<In>::TValue> TLimits;
        if (TLimits::is_specialized)
        {
            buffer_.precision(TLimits::digits10 + 1);
        }
        buffer_ << in;
    }
    const bool read(std::string& out)
    {
        if (!buffer_.good())
        {
            return false;
        }
        out = buffer_.str();
        return true;
    }
    template <typename Out> const bool read(Out& out)
    {
        if (!buffer_.good())
        {
            return false;
        }
        typedef std::numeric_limits<typename CallTraits<Out>::TValue> TLimits;
        if (TLimits::is_specialized)
        {
            buffer_.precision(TLimits::digits10 + 1);
        }
        return buffer_ >> out && (buffer_ >> std::ws).eof();
    }
private:
    std::stringstream buffer_;
};

}

template <typename Out, typename In>
Out stringCast(const In& in)
{
    impl::StringCast caster(in);
    Out out;
    if (!caster.read(out))
    {
        LASS_THROW("Failed to cast");
    }
    return out;
}

}
}


#endif

// EOF