如何确定非对象泛型的类型？

Question

显然以下代码不起作用:

....
property value: T read FTheValue;
....
function TDefiniteValue<T>.toString: string;
begin
  Result:= ' definitly ';
  if (value is TObject) then Result:= Result + TObject(value).ToString
  else if (value is integer) then Result:= Result + IntToStr(integer(value));
  //                ^^^^^^^
  //                +++++++-- integer is not an object
end;

如何比较非对象的类型？

这是一个SSCCE

Program Maybe; 

interface

uses
  System.Generics.Collections, System.SysUtils;

type    
  TDefiniteValue<T> = class(TEnumerable<T>)
  strict private
    FTheValue: T;
  strict protected
    function toString: string; override;
    property value: T read FTheValue;
  end;

implementation

function TDefiniteValue<T>.toString: string;
begin
  Result:= ' definitly ';
  if (value is TObject) then Result:= Result + TObject(value).ToString
  else if (value is integer) then Result:= Result + IntToStr(integer(value));
  //                ^^^^^^^
  //                +++++++-- integer is not an object.
end;

begin
end.

Answer 1

只需使用System.Rtti.TValue:

function TDefiniteValue<T>.ToString: string;
var
  v: TValue;
begin
  v := TValue.From<T>(FTheValue);
  Result:= ' definitly ' + v.ToString;
end;