Deduce the template parameter VALUE from the value_type of the iterators supplied to the constructor of deque. This deduction guide does not participate unless the supplied allocator is convertible to bsl::allocator<VALUE>.
Declared in <bslstl_deque.h>
template<
class INPUT_ITERATOR,
class ALLOC,
class VALUE = BloombergLP::bslstl::IteratorUtil::IterVal_t<INPUT_ITERATOR>,
class DEFAULT_ALLOCATOR = bsl::allocator<VALUE>>
requires bsl::is_convertible_v<ALLOC *, DEFAULT_ALLOCATOR>
deque<VALUE>(
INPUT_ITERATOR,
INPUT_ITERATOR,
ALLOC*) -> deque<VALUE>;