[fpc-pascal] Records

[Florian Klaempfl]

Adriaan van Os wrote:

> Carsten Bager wrote:
> 
>> We are moving a lot of code from an old platform where it is
>> allowed to compare 2 records like this.
>>
>> Type
>>   A_typ=array[0..3] of integer;
>> Var
>>  A1,A2:A_typ;
>>
>> Begin
>>   If A1=A2 then
>> End;
>>
>> I know that I can typecast to an array of char to compare but
>> is there an easier way.
>>
>> ---
>>
>> I have never could understand when this is allowed
>> A1:=A2;
>>
>> Why this is not allowed
>> If A1=A2 then
>>
>> in most Pascal compilers.
> 
> 
> Because you can't simply compare the memory ranges occupied by records A
> and B. They could have different pad bytes (and bits) but still be the
> same. Therefore, implementation is non-trivial. For the same reason, the
> above typecast is incorrect.
> 

We could implement such a comparisation based on rtti ...