CWG2954 [intro.races] p4 total order vs. strict total order

[xmh0511]

Full name of submitter (unless configured in github; will be published with the issue): Jim X

[intro.races] p4 says:

All modifications to a particular atomic object M occur in some particular total order, called the modification order of M.

According to Wikipedia, The modification order is more like a strict total order. Their difference is:

Any two modifications in the modification order are distinct elements, so they cannot be If a ≤ b and b ≤ a then a = b. In other words, either one precedes the other or after, they cannot overlap(i.e. equal). Moreover, saying a modification precedes itself(i.e. reflexive) in the order is meaningless.

Suggested Resolution:

All modifications to a particular atomic object M occur in some particular strict total order, called the modification order of M.

[atomics.order] p4

There is a single strict total order S on all memory_order​::​seq_cst operations, including fences, that satisfies the following constraints.

[frederick-vs-ja]

This strongly feels editorial to me.

[xmh0511]

cplusplus/draft#7379

[jensmaurer]

CWG2954

[opensdh]

If "two modifications in the modification order are distinct elements", they can't have a≤b and b≤a, precisely because in a (non-strict) total order we then have a=b and they aren't two modifications. a=b there doesn't mean "the two modifications occupy the same place in the order"; it means that they are two labels for the same modification.