Const template

[Andrei Alexandrescu (See Website For Email)]

Chris Nicholson-Sauls wrote:
> So then I ask, why have const constructors/destructors?  What, given 
> an (even contrived) example, would be the likely difference in code 
> between constant and non-constant constructors/destructors?  And how 
> is this:

A constructor might take different decisions on caching, preallocating
etc. when it prepares for mutability, as opposed to it knowing that the
object won't change. For example, creating a const deque might cause a 
different allocation strategy than a non-const one.

> # Foo f = new const Foo;
> 
> Different from this: # const Foo f = new Foo;

In the latter case you are robbing the constructor from a little piece 
of information. Things will still work.


Andrei