ROOT CAUSE:
The allocate() function was incorrectly constructing objects during memory
allocation, violating C++ allocator requirements. MSVC's std::_Tree_node has
a deleted default constructor, causing compilation failure.
CHANGES:
- container_allocator::allocate() now only allocates raw memory without
constructing objects (removed mem::$new and ipc::construct calls)
- container_allocator::deallocate() now only frees memory without
destroying objects (removed mem::$delete and ipc::destroy_n calls)
WHY THIS FIXES THE ISSUE:
C++ allocator semantics require strict separation:
* allocate() -> raw memory allocation only
* construct() -> object construction with proper arguments
* destroy() -> object destruction
* deallocate() -> memory deallocation only
Standard containers (like std::map) call construct() with proper arguments
(key, value) to initialize nodes, not allocate(). Since std::_Tree_node in
MSVC has no default constructor (= delete), attempting to construct it
without arguments always fails.
Fixes MSVC 2017 compilation error:
error C2280: 'std::_Tree_node<...>::_Tree_node(void)':
attempting to reference a deleted function