Created on 2024-05-14.00:00:00 last changed 2 months ago
[ 2024-06-24; Reflector poll ]
Set priority to 4 after reflector poll. See also LWG 3813.
Although volatile int* satisfies contiguous_iterator, due to the formula design of iter_const_reference_t, its result for the former will be int, which makes basic_const_iterator<volatile int*> no longer a contiguous_iterator even though its iterator_concept is defined as contiguous_iterator_tag and it has a valid operator->() that returns const volatile int*.
This seems to defeat the purpose of basic_const_iterator to preserve the behavior of the underlying iterator (except for indirection operators). The same goes for basic_const_iterator<const volatile int*>:#include <iterator> #include <span> int main() { int i = 42; const volatile int* p = &i; static_assert(std::contiguous_iterator<decltype(p)>); std::span sp1{p, 1}; // ok std::basic_const_iterator it{p}; static_assert(std::same_as<decltype(it.operator->()), const volatile int*>); static_assert(std::same_as<decltype(it)::iterator_concept, std::contiguous_iterator_tag>); static_assert(std::contiguous_iterator<decltype(it)>); // failed std::span sp2{it, 1}; // failed }
History | |||
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Date | User | Action | Args |
2024-06-24 12:09:57 | admin | set | messages: + msg14193 |
2024-05-14 00:00:00 | admin | create |