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# std::raw_storage_iterator

From cppreference.com
< cpp‎ | memory

Defined in header `<memory>` |  |
template< class OutputIt, class T > class raw_storage_iterator : public std::iterator<std::output_iterator_tag, void, void, void, void>; |  | (until C++17)
template< class OutputIt, class T > class raw_storage_iterator; |  | (since C++17)

The output iterator `std::raw_storage_iterator` makes it possible for standard algorithms to store results in uninitialized memory. Whenever the algorithm writes an object of type `T` to the dereferenced iterator, the object is copy-constructed into the location in the uninitialized storage pointed to by the iterator. The template parameter `OutputIt` is any type that meets the requirements of `OutputIterator` and has operator* defined to return an object, for which operator& returns an object of type `T*`. Usually, the type `T*` is used as `OutputIt`.

### [edit] Type requirements

- `OutputIt` must meet the requirements of `OutputIterator`.

### [edit] Member functions

(constructor) | creates a new `raw_storage_iterator` (public member function) [edit]
operator= | constructs an object at the pointed-to location in the buffer (public member function) [edit]
operator* | dereferences the iterator (public member function) [edit]
operator++operator++(int) | advances the iterator (public member function) [edit]
base (since C++17) | provides access to the wrapped iterator (public member function) [edit]

### [edit] Member types

Member type | Definition
`value_type` | void
`difference_type` | void
`pointer` | void
`reference` | void
`iterator_category` | std::output_iterator_tag

Note: before C++17, these member types are required to be obtained by inheriting from std::iterator<std::output_iterator_tag,void,void,void,void>.

### [edit] Example

Run this code

    #include <iostream>
    #include <string>
    #include <memory>
    #include <algorithm>

    int main()
    {
        const std::string s[] = {"This", "is", "a", "test", "."};
        std::string* p = std::get_temporary_buffer<std::string>(5).first;

        std::copy(std::begin(s), std::end(s),
                  std::raw_storage_iterator<std::string*, std::string>(p));

        for(std::string* i = p; i!=p+5; ++i) {
            std::cout << *i << '\n';
            i->~basic_string<char>();
        }
        std::return_temporary_buffer(p);
    }

Output:

    This
    is
    a
    test
    .

### [edit] See also

allocator_traits (C++11) | provides information about allocator types (class template) [edit]
scoped_allocator_adaptor (C++11) | implements multi-level allocator for multi-level containers (class template) [edit]
uses_allocator (C++11) | checks if the specified type supports uses-allocator construction (class template) [edit]

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