Is `alias this` a mistake?

[IGotD-]

On Thursday, 5 August 2021 at 16:46:53 UTC, H. S. Teoh wrote:
>
> In C++, this is worked around by requiring passing by reference 
> instead by value. But in D, this kinda defeats the purpose of 
> structs, the whole point of which is a by-value type that gets 
> passed around as "glorified ints", as Andrei calls it.  Once 
> you need to pass things around by reference, structs lose their 
> raison d'etre, and you might as well just use a class instead.
>

I never understood the benefit of structs are value types. In 
what use case would you like to pass the value of a struct rather 
than a reference. The struct will be copied on the stack which is 
inefficient so in 99% of the cases you would like to use the 
reference, especially when the parameter is const. If you need a 
copy the called function could be responsible for that.

Could someone explain the benefit of this "glorified int".