Maybe D was wrong on contracts

[Quirin Schroll]

On Monday, 17 August 2026 at 19:23:31 UTC, H. S. Teoh wrote:
> On Mon, Aug 17, 2026 at 06:57:04PM +0000, Quirin Schroll via 
> Digitalmars-d wrote:
>> TL;DR: D’s contracts are theoretically unsound, but there’s an 
>> easy fix.
> [...]
>> Maybe C++ got something right, or rather, D got something 
>> wrong that C++ got right-er:
>> 
>> *A virtual function’s postconditions don’t get limit what 
>> overriders do when invoked with arguments that don’t satisfy 
>> its preconditions.*
>> 
>> The violation of this principle might be the reason why D’s 
>> contracts never took off.
> [...]
>
> IMO, the reason D's contracts never took off is because they 
> are too complex to reason about when mixed with inheritance / 
> polymorphism.

They might be hard to reason about because the way they work is 
unreasonable. (Sounds like a pun, but I mean it literally.)