[fpos.operations] Unclear assertions in requirements table

[jlaire]

The first row in "Table 108 — Position type requirements" contains expression P(i) in the first column and assertion p == P(i) in the last column. It is not clear what p refers to, since it is not used in the expression. Perhaps it is a typo and the assertion should be i == P(i).

The expression streamsize(o) has a corresponding assertion streamsize(O(sz)) == sz. The meaning of this is also unclear, since sz does not appear in the expression.

[jensmaurer]

Regarding the first row: I have no clue what the editorial fix here should be. "p" is just any value of type P, so "p == P(i)" seems totally misguided. I'm asking for an LWG issue.

Regarding the conversions in the last row of the table: sz is introduced in the paragraph before the table: "sz refers to a value of type streamsize". So, these rows tell you that conversion from streamsize to streamoff, then back to streamsize is value-preserving for all possible values of type "streamsize".

[jensmaurer]

http://cplusplus.github.io/LWG/lwg-active.html#2832

[jensmaurer]

See #2134 for the wholesale cleanup here.