[cpp-threads] New strawman proposal

[Peter Dimov]

Doug Lea wrote:
> 1. In :
> 
>> Given a candidate execution, and a synchronizes with relation, we
>> define a happens-before relation on the actions in the execution as
>> the transitive closure of the union of the following relations:  
>> 
>>    1. The "synchronizes-with" relation on acquire and release
>> operations. R is related to A iff R synchronizes-with A. 
>>    2. The intra-thread execution ordering from the candidate
>> execution. A is related to B iff B follows A in the execution if a
>> single thread.  
> 
> Can we replace (2) with just
> 
>   2. An intra-thread ordering in which the sequence point of A
>      is prior to the sequence point of B.

1. A happens-before B if there is a sequence point between A and B.
2. A happens-before B if A synchronizes-with B.

(Not iff.)