lazy construction of an immutable object

[Jason den Dulk via Digitalmars-d-learn]

On Tuesday, 15 July 2014 at 12:20:57 UTC, Puming wrote:

> @property immutable(T) freeze(T)(T obj)
> {
> 	return cast(immutable(T))(obj);
> }

>> What is the idiomatic approach to do this in D?

There is a Phobos function std.exception.assumeUnique which 
performs this for arrays. According to the docs, it does what 
'freeze' does, and is considered idiomatic.

> But the draw back is that you can't garanteed that the mutable 
> object is never used.

I got the impression that assumeUnique has the same problem.

Regards