# std::scoped_allocator_adaptor<OuterAlloc,InnerAlloc...>::scoped_allocator_adaptor

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< cpp‎ | memory‎ | scoped allocator adaptor

Defined in header `<scoped_allocator>` |  |
scoped_allocator_adaptor(); | (1) | (since C++11)
template< class OuterA2 > scoped_allocator_adaptor( OuterA2&& outerAlloc, const InnerAllocs&... innerAllocs) noexcept; | (2) | (since C++11)
scoped_allocator_adaptor( const scoped_allocator_adaptor& other ) noexcept; | (3) | (since C++11)
scoped_allocator_adaptor( scoped_allocator_adaptor&& other ) noexcept; | (4) | (since C++11)
template< class OuterA2 > scoped_allocator_adaptor( const scoped_allocator_adaptor<OuterA2, InnerAllocs...>& other ) noexcept; | (5) | (since C++11)
template< class OuterA2 > scoped_allocator_adaptor( scoped_allocator_adaptor<OuterA2, InnerAllocs...>&& other ) noexcept; | (6) | (since C++11)

1) Default constructor: value-initializes the `OuterAlloc` base class and the inner allocator member object, if used by the implementation.

2) Constructs the base class `OuterAlloc` from std::forward<OuterA2>(outerAlloc), and the inner allocators with `innerAllocs...`. This overload only participates in overload resolution if std::is_constructible<OuterAlloc, OuterA2>::value is true.

3) Copy-constructor: initializes each allocator from the corresponding allocator of `other`

4) Move-constructor: moves each allocator from the corresponding allocator of `other` into `*this`

5) Initializes each allocator from the corresponding allocator of `other`. This overload only participates in overload resolution if std::is_constructible<OuterAlloc, const OuterA2&>::value is true.

6) Initializes each allocator from the corresponding allocator of `other`, using move semantics. This overload only participates in overload resolution if std::is_constructible<OuterAlloc, OuterA2>::value is true.

### Parameters

outerAlloc | - | constructor argument for the outer allocator
innerAllocs... | - | constructor arguments for the inner allocators
other | - | another `std::scoped_allocator_adaptor`

### Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR | Applied to | Behavior as published | Correct behavior
--- | --- | --- | ---
LWG 2782 | C++11 | constructors taking `OuterA2` weren't constrained, interfering with metaprogramming | constraint added

### See also

allocate | allocates uninitialized storage using the outer allocator (public member function)
construct | constructs an object in allocated storage, passing the inner allocator to its constructor if appropriate (public member function)

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