std::pmr::polymorphic_allocator<T>::new_object

Since C++20

template< class U, class... CtorArgs >
[[nodiscard]] U* new_object( CtorArgs&&... ctor_args );

Allocates and constructs an object of type U.

Given alloc is a std::pmr::polymorphic_allocator<T>:

U* p = alloc.new_object<U>(std::forward<CtorArgs>(ctor_args)...);

is equivalent to

U* p = alloc.allocate_object<U>();
try {
  alloc.construct(p, std::forward<CtorArgs>(ctor_args)...);
} catch (...) {
  alloc.deallocate_object(p);
  throw;
}

Parameters

ctor_args - the arguments to forward to the constructor of U

Return value

A pointer to the allocated and constructed object.

Notes

This function was introduced for use with the fully-specialized allocator std::pmr::polymorphic_allocator<>, but it may be useful in any specialization as a shortcut to avoid having to rebind from std::pmr::polymorphic_allocator<T> to std::pmr::polymorphic_allocator<U>, and having to call allocate, construct, and deallocate individually.

Since U is not deduced, it must be provided as a template argument when calling this function.

Exceptions

May throw any exceptions thrown by the call to allocate_object or the constructor of U.