WxExtLib - safecast_signedness.h

00001: // -*- c++ -*-
00002: 
00003: //-------------------------------------------------------------------------
00004: // Author: Daniel Käps, created 2006-01-26.
00005: // This file is public domain.
00006: //-------------------------------------------------------------------------
00007: 
00008: // no guards:
00009: // #ifndef _INCLUDED_safecast_signedness_h  
00010: // #define _INCLUDED_safecast_signedness_h  
00011: 
00012: //-------------------------------------------------------------------------
00013: //
00014: // signed/unsigned/default-signed-ness conversions:
00015: // - those are less problematic compared to type-size changes, since,
00016: //   at least, no data is lost by the cast operation
00017: // - however, wrong interpretation may cause incorrect behavior, still
00018: //
00019: // some cast difficulties with regard to signed-ness conversions:
00020: // - some compilers may interpret 'signed type' and '(unspecified 
00021: //   signedness) type' differently with regard to overload resolution
00022: // - the type of '(unspecified signedness) char' may differ from compiler 
00023: //   to compiler and may additionally depend on compiler options
00024: //
00025: //-------------------------------------------------------------------------
00026: 
00027: // used defines:
00028: //  #define M_Type ... // e.g. char, char *, int etc.
00029: //  #define M_SafecastSignedness_IsAddConstOverloads 0/1
00030: //  #define M_SafecastSignedness_IsUseDefaultSignedness 0/1
00031: 
00032: //-------------------------------------------------------------------------
00033: 
00034: // declared functions will be:
00035: //   cast_signed()
00036: //   cast_unsigned()
00037: //   cast_defsigned()
00038: // additionally with const overloads if 
00039: // M_SafecastSignedness_IsAddConstOverloads defined to 1
00040: 
00041: //=========================================================================
00042: // functions to return M_Type as unsigned type
00043: 
00044: inline unsigned M_Type cast_unsigned (signed M_Type TypeVar)
00045: {
00046:     return (unsigned M_Type) TypeVar;
00047: }
00048: 
00049: #if (M_SafecastSignedness_IsUseDefaultSignedness == 1)
00050: inline unsigned M_Type cast_unsigned (M_Type TypeVar)
00051: {
00052:     return (unsigned M_Type) TypeVar;
00053: }
00054: #endif
00055: 
00056: inline unsigned M_Type cast_unsigned (unsigned M_Type TypeVar)
00057: {
00058:     return TypeVar;
00059: }
00060: 
00061: //-------------------------------------------------------------------------
00062: 
00063: #if (M_SafecastSignedness_IsAddConstOverloads == 1)
00064: 
00065: inline const unsigned M_Type cast_unsigned (const signed M_Type TypeVar)
00066: {
00067:     return (unsigned M_Type) TypeVar;
00068: }
00069: 
00070: #if (M_SafecastSignedness_IsUseDefaultSignedness == 1)
00071: inline const unsigned M_Type cast_unsigned (const M_Type TypeVar)
00072: {
00073:     return (unsigned M_Type) TypeVar;
00074: }
00075: #endif
00076: 
00077: inline const unsigned M_Type cast_unsigned (const unsigned M_Type TypeVar)
00078: {
00079:     return TypeVar;
00080: }
00081: 
00082: #endif
00083: 
00084: //=========================================================================
00085: // functions to return M_Type as signed type
00086: 
00087: inline signed M_Type cast_signed (signed M_Type TypeVar)
00088: {
00089:     return TypeVar;
00090: }
00091: 
00092: #if (M_SafecastSignedness_IsUseDefaultSignedness == 1)
00093: inline signed M_Type cast_signed (M_Type TypeVar)
00094: {
00095:     return (signed M_Type) TypeVar;
00096: }
00097: #endif
00098: 
00099: inline signed M_Type cast_signed (unsigned M_Type TypeVar)
00100: {
00101:     return (signed M_Type) TypeVar;
00102: }
00103: 
00104: //-------------------------------------------------------------------------
00105: 
00106: #if (M_SafecastSignedness_IsAddConstOverloads == 1)
00107: 
00108: inline const signed M_Type cast_signed (const signed M_Type TypeVar)
00109: {
00110:     return TypeVar;
00111: }
00112: 
00113: #if (M_SafecastSignedness_IsUseDefaultSignedness == 1)
00114: inline const signed M_Type cast_signed (const M_Type TypeVar)
00115: {
00116:     return (signed M_Type) TypeVar;
00117: }
00118: #endif
00119: 
00120: inline const signed M_Type cast_signed (const unsigned M_Type TypeVar)
00121: {
00122:     return (signed M_Type) TypeVar;
00123: }
00124: 
00125: #endif
00126: 
00127: //=========================================================================
00128: // functions to return M_Type with default-signedness (i.e.
00129: // no signedness declarator ('signed' or 'unsigned') is used)
00130: 
00131: inline M_Type cast_defsigned (signed M_Type TypeVar)
00132: {
00133:     return (M_Type) TypeVar;
00134: }
00135: 
00136: #if (M_SafecastSignedness_IsUseDefaultSignedness == 1)
00137: inline M_Type cast_defsigned (M_Type TypeVar)
00138: {
00139:     return TypeVar;
00140: }
00141: #endif
00142: 
00143: inline M_Type cast_defsigned (unsigned M_Type TypeVar)
00144: {
00145:     return (M_Type) TypeVar;
00146: }
00147: 
00148: //-------------------------------------------------------------------------
00149: 
00150: #if (M_SafecastSignedness_IsAddConstOverloads == 1)
00151: 
00152: inline const M_Type cast_defsigned (const signed M_Type TypeVar)
00153: {
00154:     return (M_Type) TypeVar;
00155: }
00156: 
00157: #if (M_SafecastSignedness_IsUseDefaultSignedness == 1)
00158: inline const M_Type cast_defsigned (const M_Type TypeVar)
00159: {
00160:     return TypeVar;
00161: }
00162: #endif
00163: 
00164: inline const M_Type cast_defsigned (const unsigned M_Type TypeVar)
00165: {
00166:     return (M_Type) TypeVar;
00167: }
00168: 
00169: #endif
00170: 
00171: //-------------------------------------------------------------------------
00172: 
00173: // #endif
00174: