Create a variant object holding the same alternative (if any) as the specified original object. If this variant is allocator-aware, the specified allocator is used to supply memory. If the original object is not valueless by exception`, the contained value is copy-constructed from the contained value of original. This constructor is deleted unless all alternatives are copy constructible.
Declared in <bslstl_variant.h>
template<class t_FIRST = t_HEAD>
requires BloombergLP::bslstl::
Variant_IsCopyConstructibleAll<t_FIRST, t_TAIL...>::value
variant(
std::allocator_arg_t,
allocator_type allocator,
variant const& original);