allocatortraitsAllocdestroya

AllocatortraitsAllocdestroya is a proposed extension to the C++ allocator_traits framework that introduces a dedicated destruction policy, called Allocdestroya, for memory deallocation. The concept aims to separate the destruction of objects from the release of memory, allowing custom allocators to control when and how destructors are invoked during deallocation.

In this design, Allocdestroya is expressed as a policy type or an enumerated value that accompanies an allocator’s traits. Implementations can specify a policy such as DestroyOnDeallocate, SkipDestruction, or a default behavior aligned with the standard allocator_traits. The policy is consulted by deallocation paths to determine whether the destructor should be invoked before memory is released, or if destruction is handled by another mechanism.

Allocator_traits would be extended to expose the Allocdestroya policy through the allocator’s trait specialization. A deallocation routine can then conditionally invoke a destructor when the policy requires it, while other policies may bypass destruction to support allocators that manage lifetimes differently (for example, arena or pool allocators where destruction is performed in bulk or outside the allocator’s deallocation function).

Usage considerations include compatibility with existing standard library components and the potential performance impact of conditional destruction. Implementations must ensure consistent behavior across different allocators and maintain exception safety guarantees when destruction is performed. As a hypothetical extension, allocatortraitsAllocdestroya would require explicit specialization for each allocator type and clear documentation of the policy’s semantics.

See also: allocator_traits, custom allocators, memory management policies.