std::scoped_allocator_adaptor<OuterAlloc,InnerAlloc...>::construct
Template:cpp/memory/scoped allocator adaptor/sidebar Template:ddcl list begin <tr class="t-dsc-header">
<td><scoped_allocator>
<td></td> <td></td> </tr> <tr class="t-dcl ">
<td >void construct( T* p, Args&&... args )
<td > (1) </td> <td class="t-dcl-nopad"> </td> </tr> <tr class="t-dcl ">
<td >void construct( std::pair<T1, T2>* p,
std::piecewise_construct_t,
std::tuple<Args1...> x,
<td > (2) </td> <td class="t-dcl-nopad"> </td> </tr> <tr class="t-dcl ">
<td >void construct( std::pair<T1, T2>* p )
<td > (3) </td> <td class="t-dcl-nopad"> </td> </tr> <tr class="t-dcl ">
<td >void construct( std::pair<T1, T2>* p, U&& x, V&& y )
<td > (4) </td> <td class="t-dcl-nopad"> </td> </tr> <tr class="t-dcl ">
<td >void construct( std::pair<T1, T2>* p, const std::pair<U, V>& xy )
<td > (5) </td> <td class="t-dcl-nopad"> </td> </tr> <tr class="t-dcl ">
<td >void construct( std::pair<T1, T2>* p, std::pair<U, V>&& xy );
<td > (6) </td> <td class="t-dcl-nopad"> </td> </tr> Template:ddcl list end
Constructs an object in allocated, but not initialized storage pointed to by p using OuterAllocator and the provided constructor arguments. If the object is of type that itself uses allocators, or if it is std::pair, passes InnerAllocator down to the constructed object.
First, determines the outermost allocator type OUTERMOST: it is the type that would be returned by calling Template:cpp, and then calling the outer_allocator() member function recursively on the result of this call until reaching the type that has no such member function. That type is the outermost allocator.
Then:
1) If Template:cpp (the type T does not use allocators) and if Template:cpp, then calls
Otherwise, if Template:cpp (the type T uses allocators, e.g. it is a container) and if Template:cpp, then calls
Otherwise, Template:cpp (the type T uses allocators, e.g. it is a container) and if Template:cpp, then calls
Otherwise, compilation error is issued because although std::uses_allocator<T> claimed that T is allocator-aware, it lacks either form of allocator-accepting constructors.
2) First, if either T1 or T2 is allocator-aware, modifies the tuples x and y to include the appropriate inner allocator, resulting in the two new tuples xprime and yprime, according to the following three rules:
2a) if T1 is not allocator-aware (Template:cpp, then xprime is x, unmodified. (it is also required that Template:cpp)
2b) if T1 is allocator-aware (Template:cpp), and its constructor takes an allocator tag (Template:cpp, then xprime is
Template:cpp
2c) if T1 is allocator-aware (Template:cpp), and its constructor takes the allocator as the last argument (Template:cpp), then xprime is Template:cpp.
Same rules apply to T2 and the replacement of y with yprime
Once xprime and yprime are constructed (this also requires that all types in Args1... and Args2... are Template:concept), constructs the pair p in allocated storage by calling
3) Equivalent to Template:cpp, that is, passes the inner allocator on to the pair's member types if they accept them.
4) Equivalent to
5) Equivalent to
6) Equivalent to
Contents |
Parameters
| p | - | pointer to allocated, but not initialized storage |
| args... | - | the constructor arguments to pass to the constructor of T
|
| x | - | the constructor arguments to pass to the constructor of T1
|
| y | - | the constructor arguments to pass to the constructor of T2
|
| xy | - | the pair whose two members are the constructor arguments for T1 and T2
|
Return value
(none)
Notes
This function is called (through Template:cpp) by any allocator-aware object, such as Template:cpp, that was given a Template:cpp as the allocator to use. Since inner_allocator is itself an instance of Template:cpp, this function will also be called when the allocator-aware objects constructed through this function start constructing their own members.
