Re: Are throwing default constructors bad style, and if so, why?
Bart van Ingen Schenau wrote:
Andrei Alexandrescu wrote:
Bart van Ingen Schenau wrote:
In my opinion, a wrapper around an OS mutex should not have a state
where it does not own a mutex. If getting a mutex from the OS can
throw, then this wrapper class will not have any no-throw
constructors. (And using it after the destructor has returned the
mutex to the OS is a bug.)
How would you use such a mutex in a GC environment? This is a serious
question.
I would verify my program logic very carefully, to ensure that the
destructor only is called just before I release the last reference.
And I would do that for every object that needs to be explicitly
destructed/closed/whatever, just like you should do now in just about
any GC language I am familiar with. (which are not too many, to be
honest.)
The thing is, if you fail to properly verify said logic, you'll have
dangling pointers and/or leaks. A type system taking advantage of GC can
"only" have leaks.
I know that this requires the same level of attention as manual memory
management, but as you are dealing with resources that are not handled
by the GC, you have to do manual resource management anyway.
I understand. My purpose is to find a GC+determinism scheme that reduces
the work necessary and also eliminates random behavior of incorrect
programs.
Andrei
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