2025-01-22 16:18:30 +01:00

236 lines
7.3 KiB
C++

#ifndef HX_NULL_H
#define HX_NULL_H
// --- null value ---------------------------------------------------------
//
// This is used by external operatator and return statments - Most will
// use operator overloading to convert to the null pointer
// Forward declare ...
class String;
class null;
namespace hx { template<typename O> class ObjectPtr; }
namespace hx { null NullArithmetic(const char *inText); }
#define HX_NULL_COMPARE_OP(op,type,value) \
bool operator op (const type &inRHS) const { return value; }
#define HX_NULL_COMPARE_OPS(type) \
HX_NULL_COMPARE_OP(<,type,false) \
HX_NULL_COMPARE_OP(<=,type,false) \
HX_NULL_COMPARE_OP(>,type,false) \
HX_NULL_COMPARE_OP(>=,type,false) \
HX_NULL_COMPARE_OP(==,type,false) \
HX_NULL_COMPARE_OP(!=,type,true)
#define HX_NULL_COMPARE_MOST_OPS(type) \
HX_NULL_COMPARE_OP(<,type,false) \
HX_NULL_COMPARE_OP(<=,type,false) \
HX_NULL_COMPARE_OP(>,type,false) \
HX_NULL_COMPARE_OP(>=,type,false)
#define HX_COMPARE_NULL_OP(op,type,value) \
inline bool operator op (type inLHS, const null &) { return value; }
#define HX_COMPARE_NULL_OPS(type) \
HX_COMPARE_NULL_OP(<,type,false) \
HX_COMPARE_NULL_OP(<=,type,false) \
HX_COMPARE_NULL_OP(>,type,false) \
HX_COMPARE_NULL_OP(>=,type,false) \
HX_COMPARE_NULL_OP(==,type,false) \
HX_COMPARE_NULL_OP(!=,type,true)
#define HX_COMPARE_NULL_MOST_OPS(type) \
HX_COMPARE_NULL_OP(<,type,false) \
HX_COMPARE_NULL_OP(<=,type,false) \
HX_COMPARE_NULL_OP(>,type,false) \
HX_COMPARE_NULL_OP(>=,type,false)
#define HX_NULL_ARITHMETIC_OP(op) \
template<typename T> inline null operator op (T t) const \
{ return hx::NullArithmetic(#op); } \
inline null operator op (const null &) const \
{ return hx::NullArithmetic(#op); }
#define HX_ARITHMETIC_NULL_OP(op) \
template<typename T> inline null operator op (const T &, const null &) \
{ return hx::NullArithmetic(#op); }
class null
{
struct AnyArg
{
template<typename T>
inline AnyArg(const T&) { }
};
public:
inline null(){ }
template<typename T> explicit inline null(const hx::ObjectPtr<T> &){ }
template<typename T> explicit inline null(const String &){ }
explicit inline null(double){ }
explicit inline null(float){ }
explicit inline null(int){ }
explicit inline null(bool){ }
template<typename T>
T StaticCast() { return null(); }
operator bool () { return false; }
operator int () { return 0; }
operator unsigned int () { return 0; }
operator double () { return 0; }
operator float () { return 0; }
operator char () { return 0; }
operator unsigned char () { return 0; }
operator signed char () { return 0; }
operator short () { return 0; }
operator unsigned short () { return 0; }
operator cpp::UInt64 () { return 0; }
operator cpp::Int64 () { return 0; }
template<typename T>
inline operator typename hx::Native<T *> () const { return 0; }
// Any pointer!
//operator char * () { return 0; }
//operator wchar_t * () { return 0; }
template<typename T> operator T *() { return 0; }
bool operator == (null inRHS) const { return true; }
bool operator != (null inRHS) const { return false; }
bool operator == (null inRHS) { return true; }
bool operator != (null inRHS) { return false; }
template<typename T> inline bool operator == (const hx::ObjectPtr<T> &) const;
template<typename T> inline bool operator != (const hx::ObjectPtr<T> &) const;
template<typename T> inline bool operator == (const Array<T> &) const;
template<typename T> inline bool operator != (const Array<T> &) const;
inline bool operator == (const hx::FieldRef &) const;
inline bool operator != (const hx::FieldRef &) const;
inline bool operator == (const hx::IndexRef &) const;
inline bool operator != (const hx::IndexRef &) const;
inline bool operator == (const Dynamic &) const;
inline bool operator != (const Dynamic &) const;
inline bool operator == (const String &) const;
inline bool operator != (const String &) const;
inline bool operator == (const cpp::Variant &v) const { return v.isNull(); }
inline bool operator != (const cpp::Variant &v) const{ return !v.isNull(); }
inline null operator - () const { return hx::NullArithmetic("-"); }
inline null operator ! () const { return hx::NullArithmetic("!"); }
template<class T> T operator()(const AnyArg &a0=0, const AnyArg &a1=0, const AnyArg &a2=0,
const AnyArg &a4=0, const AnyArg &a5=0, const AnyArg &a6=0,
const AnyArg &a7=0, const AnyArg &a8=0, const AnyArg &a9=0 )
{
hx::NullReference("Function Call", false);
T nullDynamic;
return nullDynamic;
}
HX_NULL_COMPARE_OPS(bool)
HX_NULL_COMPARE_OPS(double)
HX_NULL_COMPARE_OPS(float)
HX_NULL_COMPARE_OPS(int)
HX_NULL_COMPARE_OPS(unsigned int)
HX_NULL_COMPARE_OPS(short)
HX_NULL_COMPARE_OPS(unsigned short)
HX_NULL_COMPARE_OPS(signed char)
HX_NULL_COMPARE_OPS(unsigned char)
HX_NULL_COMPARE_OPS(cpp::Int64)
HX_NULL_COMPARE_OPS(cpp::UInt64)
HX_NULL_COMPARE_MOST_OPS(String)
HX_NULL_COMPARE_MOST_OPS(Dynamic)
HX_NULL_COMPARE_MOST_OPS(hx::FieldRef)
HX_NULL_COMPARE_MOST_OPS(hx::IndexRef)
HX_NULL_COMPARE_OP(<,null,false)
HX_NULL_COMPARE_OP(<=,null,true)
HX_NULL_COMPARE_OP(>,null,false)
HX_NULL_COMPARE_OP(>=,null,true)
HX_NULL_ARITHMETIC_OP(+);
HX_NULL_ARITHMETIC_OP(*);
HX_NULL_ARITHMETIC_OP(-);
HX_NULL_ARITHMETIC_OP(/);
HX_NULL_ARITHMETIC_OP(%);
HX_NULL_ARITHMETIC_OP(&);
HX_NULL_ARITHMETIC_OP(|);
HX_NULL_ARITHMETIC_OP(^);
HX_NULL_ARITHMETIC_OP(>>);
HX_NULL_ARITHMETIC_OP(<<);
};
namespace hx
{
template<typename T>
struct Null
{
inline Null() : isNull(true) { }
inline Null(const Null<T> &inOther) : isNull(inOther.isNull), value(inOther.value) { }
inline Null(const T& inVal) : isNull(false), value(inVal) { }
inline Null(const null &) : isNull(true) { }
inline Null(const Dynamic &inVal)
{
isNull = null() == inVal;
if (!isNull)
value = inVal;
}
inline Null(const cpp::Variant &inVal)
{
isNull = inVal.isNull();
if (!isNull)
value = inVal;
}
inline operator Dynamic();
inline T Default(T inDefault) { return isNull ? inDefault : value; }
bool isNull;
T value;
};
} // end namesapce hx
typedef null Void;
HX_COMPARE_NULL_OPS(bool)
HX_COMPARE_NULL_OPS(double)
HX_COMPARE_NULL_OPS(float)
HX_COMPARE_NULL_OPS(int)
HX_COMPARE_NULL_OPS(unsigned int)
HX_COMPARE_NULL_OPS(short)
HX_COMPARE_NULL_OPS(unsigned short)
HX_COMPARE_NULL_OPS(signed char)
HX_COMPARE_NULL_OPS(unsigned char)
HX_COMPARE_NULL_OPS(cpp::UInt64)
HX_COMPARE_NULL_OPS(cpp::Int64)
HX_ARITHMETIC_NULL_OP(+)
HX_ARITHMETIC_NULL_OP(*)
HX_ARITHMETIC_NULL_OP(-)
HX_ARITHMETIC_NULL_OP(/)
HX_ARITHMETIC_NULL_OP(%)
HX_ARITHMETIC_NULL_OP(&)
HX_ARITHMETIC_NULL_OP(|)
HX_ARITHMETIC_NULL_OP(^)
HX_ARITHMETIC_NULL_OP(>>)
HX_ARITHMETIC_NULL_OP(<<)
// Other ops in Operator.h
inline void *_hx_nullptr() { return 0; }
#endif