[#CBB95C4AA66064CD9D12A3AF73D0967B5385D747]
Assignment
params_ref& operator=(params_ref const& other);
The previous contents of this are replaced by the contents of `other.
All iterators are invalidated.
The strings referenced by `other` must not come from the underlying url, or else the behavior is undefined.
this->assign( other.begin(), other.end() );
Linear in `other.buffer().size()`.
Strong guarantee. Calls to allocate may throw.