Delphi XE：类构造函数在使用泛型的类中不会被调用 [英] Delphi XE: class constructor doesn't get called in a class using generics

问题描述

考虑以下示例（我使用的是Delphi XE）：

Consider the following example (I am using Delphi XE):

program Test;

{$APPTYPE CONSOLE}

type
  TTestClass<T> = class
  private
    class constructor CreateClass();
  public
    constructor Create();
  end;

class constructor TTestClass<T>.CreateClass();
begin
  // class constructor is not called. this line never gets executed!
  Writeln('class created');
end;

constructor TTestClass<T>.Create();
begin
  // this line, of course, is printed
  Writeln('instance created');
end;

var
  test: TTestClass<Integer>;

begin
  test := TTestClass<Integer>.Create();
  test.Free();
end.

类构造函数从不被调用，因此不会打印创建类行。
但是，如果我删除泛化，并将 TTestClass< T> 转换为标准类 TTestClass 正如预期的那样工作。

The class constructur is never called and hence the line 'class created' is not printed. However, if I remove the generalisation and make TTestClass<T> into a standard class TTestClass, everything works as expected.

我是用泛型缺失的东西吗？或者它根本不起作用？

Am I missing something out with generics? Or it simply doesn't work?

任何关于这一点的想法都会被呵护！

Any thoughts on this would be apprechiated!

谢谢，
--Stefan -

Thanks, --Stefan--

推荐答案

看起来像一个编译器错误。如果将TTestClass声明和实现移动到单独的单元，相同的代码可以工作。

Looks like a compiler bug. The same code works if you move the TTestClass declaration and implementation to a separate unit.

unit TestClass;

interface
type
  TTestClass<T> = class
  private
    class constructor CreateClass();
  public
    constructor Create();
  end;

var
  test: TTestClass<Integer>;

implementation

class constructor TTestClass<T>.CreateClass();
begin
  Writeln('class created');
end;

constructor TTestClass<T>.Create();
begin
  Writeln('instance created');
end;

end.

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