EnumHelper.h

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#ifndef EnumHelper_H
#define EnumHelper_H

/*
 * Safely add an integer to an enum.
 *
 * This is illegal:
 *
 *  ((int&)val) += iAmt;
 *
 * It breaks aliasing rules; the compiler is allowed to assume that "val" doesn't
 * change (unless it's declared volatile), and in some cases, you'll end up getting
 * old values for "val" following the add.  (What's probably really happening is
 * that the memory location is being added to, but the value is stored in a register,
 * and breaking aliasing rules means the compiler doesn't know that the register
 * value is invalid.)
 *
 * Always do these conversions through a union.
 */
template<typename T>
static inline void enum_add( T &val, int iAmt )
{
        union conv
        {
                T value;
                int i;
        };

        conv c;
        c.value = val;
        c.i += iAmt;
        val = c.value;
}

#define FOREACH_ENUM( e, max, var )     for( e var=(e)0; var<max; enum_add<e>( var, +1 ) )


static const CString EMPTY_STRING;

#define XToString(X)    \
        const CString& X##ToString( X x ) \
        {       \
                if( x == ARRAYSIZE(X##Names)+1 )        \
                        return EMPTY_STRING;    \
                ASSERT(unsigned(x) < ARRAYSIZE(X##Names));      \
                return X##Names[x];     \
        }

#define XToThemedString(X)      \
        CString X##ToThemedString( X x ) \
        {       \
                return THEME->GetMetric( #X, X##ToString(x) );  \
        }

#define StringToX(X)    \
        X StringTo##X( const CString& s ) \
        {       \
                CString s2 = s; \
                s2.MakeLower(); \
        unsigned i; \
                for( i = 0; i < ARRAYSIZE(X##Names); ++i )      \
                        if( !s2.CompareNoCase(X##Names[i]) )    \
                                return (X)i;    \
                return (X)(i+1); /*invalid*/    \
        }

#endif

/*
 * (c) 2004 Chris Danford
 * All rights reserved.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, and/or sell copies of the Software, and to permit persons to
 * whom the Software is furnished to do so, provided that the above
 * copyright notice(s) and this permission notice appear in all copies of
 * the Software and that both the above copyright notice(s) and this
 * permission notice appear in supporting documentation.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF
 * THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS
 * INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT
 * OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
 * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

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