Constructor inheritance? Why not?

[Paulo Pinto via Digitalmars-d]

On Monday, 8 June 2015 at 09:20:06 UTC, Ola Fosheim Grøstad wrote:
> On Monday, 8 June 2015 at 06:35:33 UTC, Jonathan M Davis wrote:
>> On Monday, 8 June 2015 at 06:04:23 UTC, Tofu Ninja wrote:
>>> No its definitely not something that alot of people seem to 
>>> care about, but I always found it odd that constructors get 
>>> certain special casing like this.
>>
>> I expect that it originally comes down to the fact that 
>> constructors aren't polymorphic and _can't_ be polymorphic.
>
> They can if you use type variables. Type variables can be 
> virtual too.
>
>> When you override a function, you're overriding the one in the 
>> base class and replacing its implementation. You can choose to 
>> call the base class' version of the function, but you don't 
>> have to. You're dynamically replacing a function.
>
> Conceptually you should. In Simula's successor Beta you had to, 
> but you had "inner" inheritance opposed to Simula/C++ "outer" 
> inheritance. E.g. the logic of the subclass is executed by the 
> superclass. It is much cleaner, actually.
>
>> So, yes, constructors _are_ fundamentally different from other 
>> functions. And the inheritance that you get with constructors 
>> is not at all what you get when you override a function. 
>> They're at most superficially similar. And older languages 
>> such as C++98 and Java don't have inherited constructors. 
>> They're a relatively new idea.
>
> Let's not rewrite history, shall we? Constructors are not 
> fundamentally different from other functions by nature. In 
> minimal OO languages there is no significant difference between 
> the definition of a class/constructor and a function.

Yep, in Modula-3 and Oberon, one even has to create the VMT 
explicitly.

--
Paulo