Re: [Boost-users] Issues with boost::process from the sandbox and the boost::process::child semantics

On Mon, Mar 28, 2011 at 12:24 PM, Dominique Devienne wrote:

On Sun, Mar 27, 2011 at 4:01 PM, Jan Kundrát wrote:

...

It turns out that the boost::process::child class is missing a default constructor...

I don't see the lack of a default constructor as a design flaw here.

I agree. What should be the meaning of a default-constructed boost::process::child? Which of the normal invariants still hold when the object is default-constructed? It seems to me that you're asking for the 'child' class to store a flag: is this a real instance or a placeholder instance? Then every access to that object must check the flag. By factoring out the flag to boost::optional, the semantics of the boost::process::child class are improved.