Re: [boost] [review] string convert

Subject: Re: [boost] [review] string convert
From: Vladimir Batov (vbatov_at_[hidden])
Date: 2011-05-06 19:46:55

> From: "Jeremy Maitin-Shepard" <jeremy_at_[hidden]>
> The fact that built-in types in C++ have a special "uninitialized" state 
> separate from the default constructed state necessary makes them a special 
> case.  Nonetheless, a default constructor is often useful even if it 
> serves to create an arbitrary initial state with only the guarantee that 
> it won't leak memory, etc.

In my nick of the woods that is not a sufficient guarantee. That requires 
*all* the code dealing with the relevant object to have checks if that 
object indeed has been constructed properly and has value or it just "won't 
leak memory". That is a case similar to pointers vs. references debate.

> Basically it allows the type to serve as its own optional<>, with the 
> caveat that you cannot check if it has been initialized and don't need to 
> dereference it explicitly.

When I need optional<>, I'll use optional<>.

> This often is more convenient/leads to better syntax that having to use 
> optional<> or a smart pointer of some type everywhere.

I disagree. In my view it leads to avoidable and error-prone code where I 
forget to check if the passed-in object has, in-fact, a valid state and 
proceed using it.

> For instance, arrays (and some other containers) require a default 
> constructor.

I knew containers will come up as an example sooner and later. An empty 
container is a valid object in a useble state. There is nothing optional 
about it.

V.