指向通用记录的指针 [英] Pointer to generic record

问题描述

请注意，这不是指向泛型类型的指针的重复。这是一个后续问题。

我知道可以定义一个指向任何泛型类型的指针。

它只是让Delphi变得复杂。这意味着不可能，但是由于编译器错误，该选项会滑过。

这是链接问题的答案。

我的问题是：

如何定义指向通用记录的指针而不封装它在周围的类中？

示例代码：

  TGenericRecord< T> =记录
数据：整数; 
程序SomeMethod;一致; <<<<内联在这里至关重要。 
 end; 
  

我想获得一个类型安全的TGenericRecord指针。 strong> not 想要将该记录包装在周围的类中，因为在我的实验中，我发现这会禁用内联。

如何获得类型安全的通用指针到这条记录。

用例

  {class } function create（size：integer）：PGenericRecord {< T>} 
  

我希望能够除堆栈外还在堆上创建记录。

解决方案

我认为你最好的选择可能看起来像这样：

 键入
 TMyStaticClass< T> = class 
 public 
 type 
 TRec =记录
 .... 
 end; 
 PRec = ^ TRec; 
 public 
类函数NewRec：PRec;静态的; 
 end; 
  

我没有编译器方便检查这个编译是否甚至编译，但我觉得它应该.....

Note that this is not a duplicate of Pointer to generic type. It's a followup question.

I know it is possible to define a pointer to any generic type.
It just that Delphi makes it complicated. It was meant to be impossible, but due to a compiler bug the option slipped through.
This is what the linked question answers.

My question is:

How do I define a pointer to a generic record without encapsulating it in a surrounding class?

Example code:

TGenericRecord<T> = record
  Data: integer;
  Procedure SomeMethod; inline; <<<< inlining is vital here. 
end;

I want to get a type safe pointer to TGenericRecord.
I do not want to wrap the record in a surrounding class because in my experiments I've found that that disables the inlining.

How do I get a typesafe generic pointer to this record.

Use case

{class} function create(size: integer): PGenericRecord{<T>}

I want to be able to create records on the heap in addition to the stack.

解决方案

I think your best bet probably looks like this:

type 
  TMyStaticClass<T> = class
  public
    type
      TRec = record
        ....
      end;
      PRec = ^TRec;
  public
    class function NewRec: PRec; static;
  end;

I don't have a compiler handy to check whether or not this even compiles but I feel that it should.....

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