stringize.h

/**
 * @file   stringize.h
 * @author Nat Goodspeed
 * @date   2008-12-17
 * @brief  stringize(item) template function and STRINGIZE(expression) macro
 * 
 * $LicenseInfo:firstyear=2008&license=viewergpl$
 * Copyright (c) 2008, Linden Research, Inc.
 * $/LicenseInfo$
 */

#if ! defined(LL_STRINGIZE_H)
#define LL_STRINGIZE_H

#include <sstream>
#include <boost/lambda/lambda.hpp>

/**
 * stringize(item) encapsulates an idiom we use constantly, using
 * operator<<(std::ostringstream&, TYPE) followed by std::ostringstream::str()
 * to render a string expressing some item.
 */
template <typename T>
std::string stringize(const T& item)
{
    std::ostringstream out;
    out << item;
    return out.str();
}

/**
 * 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::lambda::_1 << 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::lambda::_1 >> EXPRESSION)))


#endif /* ! defined(LL_STRINGIZE_H) */