What is the current stage of @property ?

[Paul Backus]

On Wednesday, 10 June 2020 at 23:03:21 UTC, Adam D. Ruppe wrote:
> On Wednesday, 10 June 2020 at 22:50:17 UTC, Paul Backus wrote:
>> static assert(isInputRange!S); // passes
>
> isInputRange doesn't check it but others do. 
> std.random.isSeedable requires @property on front for example.

Nope:

struct S {
     bool empty() { return false; }
     int front() { return 0; }
     void popFront() {}
     enum bool isUniformRandom = true;
     void seed(int s) {}
}
	
static assert(isSeedable!(S, int));