phoenix-firestorm/indra/llcommon/stringize.h

151 lines
3.8 KiB
C++

/**
* @file stringize.h
* @author Nat Goodspeed
* @date 2008-12-17
* @brief stringize(item) template function and STRINGIZE(expression) macro
*
* $LicenseInfo:firstyear=2008&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2010, Linden Research, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License only.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
#if ! defined(LL_STRINGIZE_H)
#define LL_STRINGIZE_H
#include <sstream>
#include <boost/phoenix/phoenix.hpp>
#include <llstring.h>
/**
* gstringize(item) encapsulates an idiom we use constantly, using
* operator<<(std::ostringstream&, TYPE) followed by std::ostringstream::str()
* or their wstring equivalents
* to render a string expressing some item.
*/
template <typename CHARTYPE, typename T>
std::basic_string<CHARTYPE> gstringize(const T& item)
{
std::basic_ostringstream<CHARTYPE> out;
out << item;
return out.str();
}
/**
*partial specialization of stringize for handling wstring
*TODO: we should have similar specializations for wchar_t[] but not until it is needed.
*/
inline std::string stringize(const std::wstring& item)
{
LL_WARNS() << "WARNING: Possible narrowing" << LL_ENDL;
std::string s;
s = wstring_to_utf8str(item);
return gstringize<char>(s);
}
/**
* Specialization of gstringize for std::string return types
*/
template <typename T>
std::string stringize(const T& item)
{
return gstringize<char>(item);
}
/**
* Specialization for generating wstring from string.
* Both a convenience function and saves a miniscule amount of overhead.
*/
inline std::wstring wstringize(const std::string& item)
{
return gstringize<wchar_t>(item.c_str());
}
/**
* Specialization of gstringize for std::wstring return types
*/
template <typename T>
std::wstring wstringize(const T& item)
{
return gstringize<wchar_t>(item);
}
/**
* stringize_f(functor)
*/
template <typename Functor>
std::string stringize_f(Functor const & f)
{
std::ostringstream out;
f(out);
return out.str();
}
/**
* STRINGIZE(item1 << item2 << item3 ...) effectively expands to the
* following:
* @code
* std::ostringstream out;
* out << item1 << item2 << item3 ... ;
* return out.str();
* @endcode
*/
#define STRINGIZE(EXPRESSION) (stringize_f(boost::phoenix::placeholders::arg1 << EXPRESSION))
/**
* destringize(str)
* defined for symmetry with stringize
* *NOTE - this has distinct behavior from boost::lexical_cast<T> regarding
* leading/trailing whitespace and handling of bad_lexical_cast exceptions
*/
template <typename T>
T destringize(std::string const & str)
{
T val;
std::istringstream in(str);
in >> val;
return val;
}
/**
* destringize_f(str, functor)
*/
template <typename Functor>
void destringize_f(std::string const & str, Functor const & f)
{
std::istringstream in(str);
f(in);
}
/**
* DESTRINGIZE(str, item1 >> item2 >> item3 ...) effectively expands to the
* following:
* @code
* std::istringstream in(str);
* in >> item1 >> item2 >> item3 ... ;
* @endcode
*/
#define DESTRINGIZE(STR, EXPRESSION) (destringize_f((STR), (boost::phoenix::placeholders::arg1 >> EXPRESSION)))
#endif /* ! defined(LL_STRINGIZE_H) */