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Section: 18.104.22.168.2 [span.cons] Status: C++20 Submitter: Casey Carter Opened: 2019-12-10 Last modified: 2021-02-25
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[span.cons] paragraphs 6 and 9:
Throws: When and what to_address(first) throws.
could equivalently be "Throws: Nothing." since all overloads of std::to_address are noexcept. However, paragraph 9 fails to account for the fact that paragraph 8:
Effects: Initializes data_ with to_address(first) and size_ with last - first.
must evaluate last - first.
[2020-01-14 Status set to Tentatively Ready after ten positive votes on the reflector.]
[2020-01-14; Daniel comments]
The fixed wording in 22.214.171.124.2 [span.cons] p9 depends on the no-throw-guarantee of integer-class conversions to integral types. This guarantee is specified by LWG 3367.
This wording is relative to N4842.
Modify 126.96.36.199.2 [span.cons] paragraphs 6 and 9 as indicated:
The missing paragraph number of the Preconditions element at p7/p8 has already been reported as editorial issue
The effective change to "Throws: Nothing." in p6 has already been applied editorially.
template<class It> constexpr span(It first, size_type count);
[…]-4- Preconditions: […] -5- Effects: Initializes data_ with to_address(first) and size_ with count. -6- Throws:
When and what to_address(first) throws.template<class It, class End> constexpr span(It first, End last);
[…]-?- Preconditions: […] -8- Effects: Initializes data_ with to_address(first) and size_ with last - first. -9- Throws: When and what