TVariantManager defines entry points for variant conversion routines and other procedures that define variant behavior.

TVariantManager = record
  VarClear: procedure(var V : Variant);
  VarCopy: procedure(var Dest: Variant; const Source: Variant);
  VarCopyNoInd: procedure;
  VarCast: procedure(var Dest: Variant; const Source: Variant; VarType: Integer);
  VarCastOle: procedure(var Dest: Variant; const Source: Variant; VarType: Integer);
  VarToInt: function(const V: Variant): Integer;
  VarToInt64: function(const V: Variant): Int64;
  VarToBool: function(const V: Variant): Boolean;
  VarToReal: function(const V: Variant): Extended;
  VarToCurr: function(const V: Variant): Currency;
  VarToPStr: procedure(var S; const V: Variant);
  VarToLStr: procedure(var S: string; const V: Variant);
  VarToWStr: procedure(var S: WideString; const V: Variant);
  VarToIntf: procedure(var Unknown: IInterface; const V: Variant);
  VarToDisp: procedure(var Dispatch: IDispatch; const V: Variant);
  VarToDynArray: procedure(var DynArray: Pointer; const V: Variant; TypeInfo: Pointer);
  VarFromInt: procedure(var V: Variant; const Value: Integer; const Range: ShortInt);
  VarFromInt64: procedure(var V: Variant; const Value: Int64);
  VarFromBool: procedure(var V: Variant; const Value: Boolean);
  VarFromReal: procedure;
  VarFromTDateTime: procedure;
  VarFromCurr: procedure;
  VarFromPStr: procedure(var V: Variant; const Value: ShortString);
  VarFromLStr: procedure(var V: Variant; const Value: string);
  VarFromWStr: procedure(var V: Variant; const Value: WideString);
  VarFromIntf: procedure(var V: Variant; const Value: IInterface);
  VarFromDisp: procedure(var V: Variant; const Value: IDispatch);
  VarFromDynArray: procedure(var V: Variant; const DynArray: Pointer; TypeInfo: Pointer);
  OleVarFromPStr: procedure(var V: OleVariant; const Value: ShortString);
  OleVarFromLStr: procedure(var V: OleVariant; const Value: string);
  OleVarFromVar: procedure(var V: OleVariant; const Value: Variant);
  OleVarFromInt: procedure(var V: OleVariant; const Value: Integer; const Range: ShortInt);
  OleVarFromInt64: procedure(var V: OleVariant; const Value: Int64);
  VarOp: procedure(var Left: Variant; const Right: Variant; OpCode: TVarOp);
  VarCmp: procedure(const Left, Right: TVarData; const OpCode: TVarOp);
  VarNeg: procedure(var V: Variant);
  VarNot: procedure(var V: Variant);
  DispInvoke: procedure(Dest: PVarData; const Source: TVarData; CallDesc: PCallDesc; Params: Pointer);
  VarAddRef: procedure(var V: Variant);
  VarArrayRedim: procedure(var A : Variant; HighBound: Integer);
  VarArrayGet: function(var A: Variant; IndexCount: Integer; Indices: Integer): Variant;
  VarArrayPut: procedure(var A: Variant; const Value: Variant; IndexCount: Integer; Indices: Integer);
  WriteVariant: function(var T: Text; const V: Variant; Width: Integer): Pointer;
  Write0Variant: function(var T: Text; const V: Variant): Pointer;
end;

struct TVariantManager {
  procedure(var V : Variant) VarClear;
  procedure(var Dest: Variant; const Source: Variant) VarCopy;
  procedure VarCopyNoInd;
  procedure(var Dest: Variant; const Source: Variant; VarType: Integer) VarCast;
  procedure(var Dest: Variant; const Source: Variant; VarType: Integer) VarCastOle;
  function(const V: Variant): Integer VarToInt;
  function(const V: Variant): Int64 VarToInt64;
  function(const V: Variant): Boolean VarToBool;
  function(const V: Variant): Extended VarToReal;
  function(const V: Variant): Currency VarToCurr;
  procedure(var S; const V: Variant) VarToPStr;
  procedure(var S: string; const V: Variant) VarToLStr;
  procedure(var S: WideString; const V: Variant) VarToWStr;
  procedure(var Unknown: IInterface; const V: Variant) VarToIntf;
  procedure(var Dispatch: IDispatch; const V: Variant) VarToDisp;
  procedure(var DynArray: Pointer; const V: Variant; TypeInfo: Pointer) VarToDynArray;
  procedure(var V: Variant; const Value: Integer; const Range: ShortInt) VarFromInt;
  procedure(var V: Variant; const Value: Int64) VarFromInt64;
  procedure(var V: Variant; const Value: Boolean) VarFromBool;
  procedure VarFromReal;
  procedure VarFromTDateTime;
  procedure VarFromCurr;
  procedure(var V: Variant; const Value: ShortString) VarFromPStr;
  procedure(var V: Variant; const Value: string) VarFromLStr;
  procedure(var V: Variant; const Value: WideString) VarFromWStr;
  procedure(var V: Variant; const Value: IInterface) VarFromIntf;
  procedure(var V: Variant; const Value: IDispatch) VarFromDisp;
  procedure(var V: Variant; const DynArray: Pointer; TypeInfo: Pointer) VarFromDynArray;
  procedure(var V: OleVariant; const Value: ShortString) OleVarFromPStr;
  procedure(var V: OleVariant; const Value: string) OleVarFromLStr;
  procedure(var V: OleVariant; const Value: Variant) OleVarFromVar;
  procedure(var V: OleVariant; const Value: Integer; const Range: ShortInt) OleVarFromInt;
  procedure(var V: OleVariant; const Value: Int64) OleVarFromInt64;
  procedure(var Left: Variant; const Right: Variant; OpCode: TVarOp) VarOp;
  procedure(const Left, Right: TVarData; const OpCode: TVarOp) VarCmp;
  procedure(var V: Variant) VarNeg;
  procedure(var V: Variant) VarNot;
  procedure(Dest: PVarData; const Source: TVarData; CallDesc: PCallDesc; Params: Pointer) DispInvoke;
  procedure(var V: Variant) VarAddRef;
  procedure(var A : Variant; HighBound: Integer) VarArrayRedim;
  function(var A: Variant; IndexCount: Integer; Indices: Integer): Variant VarArrayGet;
  procedure(var A: Variant; const Value: Variant; IndexCount: Integer; Indices: Integer) VarArrayPut;
  function(var T: Text; const V: Variant; Width: Integer): Pointer WriteVariant;
  function(var T: Text; const V: Variant): Pointer Write0Variant;
};