Head Const

[Bottled Gin via Digitalmars-d]

Greetings

Having coded a multithreaded library in D, I sorely miss headcost 
like specifier.

The library code dealt with lots of composite class object 
hierarchy where many element objects of a parent are *effectively 
immutable*. You build an effectively immutable object in the 
constructor of the parent class and then you are done since you 
do not assign to these object handles again. As a result there is 
no need to lock the parent object while accessing an *effectively 
immutable* object. The parent as well as child objects are 
mutable otherwise.

Dlang's immutable and const do not provide such a contract.

So +1 for headconst if this specifier can be used with class 
elements as well and not just in the function parameter list.

- Puneet