Re: [boost] [atomic] Structs with default constructor

Subject: Re: [boost] [atomic] Structs with default constructor
From: Tim Blechmann (tim_at_[hidden])
Date: 2014-07-07 08:23:13

>> Boost.Atomic 1.55 accepted structs with a user-defined default constructor
>> as template argument, the version from the 1.56 test build doesn't (because
>> of the union_cast). Is this by design? I could be wrong, but I thought the
>> only requirement for structs to use them in atomics was that they were
>> trivially coyable.
> 
> Yes, this is the property of the current implementation. The type has to be 
> trivial (3.9/9). The previous versions compiled with types with non-trivial 
> default constructors but the constructors were not actually called.

andrey, the standard requires that the type is trivially copyable, but
it allows non-trivial constructors. this should be fixed for the 1.56
release, especially as it breaks existing code (including boost.lockfree).

tim