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Serialize std::shared_ptr and std::weak_ptr (sstsimulator#1352)
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11 files changed

+1050
-11
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11 files changed

+1050
-11
lines changed

‎src/sst/core/Makefile.am‎

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@@ -108,6 +108,8 @@ nobase_dist_sst_HEADERS = \
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serialization/impl/ser_buffer_accessor.h \
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serialization/impl/serialize_insertable.h \
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serialization/impl/serialize_optional.h \
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serialization/impl/ser_shared_ptr_tracker.h \
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serialization/impl/serialize_shared_ptr.h \
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serialization/impl/serialize_tuple.h \
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serialization/impl/serialize_unique_ptr.h \
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serialization/impl/serialize_utility.h \
@@ -236,10 +238,12 @@ sst_core_sources = \
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serialization/serializable.cc \
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serialization/serializer.cc \
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serialization/impl/unpacker.cc \
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serialization/impl/ser_shared_ptr_tracker.cc \
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serialization/statics.cc \
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serialization/impl/mapper.cc \
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serialization/impl/serialize_array.cc \
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serialization/impl/serialize_trivial.cc \
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serialization/impl/serialize_shared_ptr.cc \
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sstinfo.h \
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interfaces/TestEvent.cc \
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interfaces/stdMem.cc \

‎src/sst/core/serialization/impl/packer.h‎

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#include "sst/core/serialization/impl/get_array_size.h"
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#include "sst/core/serialization/impl/ser_buffer_accessor.h"
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#include "sst/core/serialization/impl/ser_shared_ptr_tracker.h"
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#include <cstdint>
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#include <cstring>
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namespace SST::Core::Serialization::pvt {
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class ser_packer : public ser_buffer_accessor
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class ser_packer : public ser_buffer_accessor, public ser_shared_ptr_packer
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{
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std::set<uintptr_t> pointer_set;
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‎src/sst/core/serialization/impl/ser_shared_ptr_tracker.cc‎

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// Copyright 2009-2025 NTESS. Under the terms
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// of Contract DE-NA0003525 with NTESS, the U.S.
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// Government retains certain rights in this software.
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//
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// Copyright (c) 2009-2025, NTESS
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// All rights reserved.
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//
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// This file is part of the SST software package. For license
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// information, see the LICENSE file in the top level directory of the
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// distribution.
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#include "sst_config.h"
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#include "sst/core/output.h"
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#include "sst/core/serialization/serializer.h"
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#include <cstddef>
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#include <memory>
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#include <utility>
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namespace SST::Core::Serialization::pvt {
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// Get the tag associated with a shared pointer's owner, and whether it is new
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std::pair<size_t, bool>
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ser_shared_ptr_packer::get_shared_ptr_owner_tag(const std::weak_ptr<const void>& ptr)
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{
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// Look for the owner of the control block in the map, creating a new owner tag if it doesn't exist
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// If there is no control block because ptr is empty, a tag of 0 is returned from the map
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auto [it, is_new_tag] = shared_ptr_map.try_emplace(ptr, owner_tag);
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// If a new entry was added, increment the owner tag for the next time a new tag is added
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if ( is_new_tag ) ++owner_tag;
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// Return the tag of the control block's owner and whether it is new
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return { it->second, is_new_tag };
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}
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// Get a reference to the std::shared_ptr<void> owner associated with a tag, and whether it is new
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std::pair<std::shared_ptr<void>&, bool>
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ser_shared_ptr_unpacker::get_shared_ptr_owner(size_t tag)
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{
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// Should never get here if the tag is 0
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if ( tag != 0 ) {
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// Get the current largest tag
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size_t num_owners = shared_ptr_owners.size();
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// If the tag has been seen before, return the owner associated with the tag
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if ( --tag < num_owners ) return { shared_ptr_owners[tag], false };
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// The first time a new tag is seen, it must be 1 higher than the max seen so far (restricted growth sequence)
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// A null pointer and a NOP deleter are used so that the new std::shared_ptr owner has a unique control block
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// If the returned std::shared_ptr owner is assigned to, the pointer and deleter will change to another owner
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if ( tag == num_owners ) return { shared_ptr_owners.emplace_back(nullptr, [](void*) {}), true };
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}
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Output::getDefaultObject().fatal(
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__LINE__, __FILE__, __func__, 1, "Serialization Error: std::shared_ptr ownership tag is out of order");
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}
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} // namespace SST::Core::Serialization::pvt

‎src/sst/core/serialization/impl/ser_shared_ptr_tracker.h‎

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// Copyright 2009-2025 NTESS. Under the terms
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// of Contract DE-NA0003525 with NTESS, the U.S.
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// Government retains certain rights in this software.
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//
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// Copyright (c) 2009-2025, NTESS
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// All rights reserved.
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//
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// This file is part of the SST software package. For license
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// information, see the LICENSE file in the top level directory of the
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// distribution.
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#ifndef SST_CORE_SERIALIZATION_IMPL_SER_SHARED_PTR_TRACKER_H
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#define SST_CORE_SERIALIZATION_IMPL_SER_SHARED_PTR_TRACKER_H
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#ifndef SST_INCLUDING_SERIALIZER_H
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#warning \
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"The header file sst/core/serialization/impl/ser_shared_ptr_tracker.h should not be directly included as it is not part of the stable public API. The file is included in sst/core/serialization/serializer.h"
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#endif
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#include "sst/core/output.h"
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#include <cstddef>
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#include <deque>
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#include <map>
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#include <memory>
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#include <utility>
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namespace SST::Core::Serialization::pvt {
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class ser_shared_ptr_packer
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{
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// Map of ownership from std::shared_ptr or std::weak_ptr to a numeric tag representing the owner
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//
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// The std::owner_less<void> functor compares two std::shared_ptr or std::weak_ptr instances with .owner_before()
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// to form an ordering which std::map uses to detect whether two std::shared_ptr or std::weak_ptr pointers have
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// the same owner.
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//
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// The keys are of type std::weak_ptr<const void> because any std::shared_ptr or std::weak_ptr can be implicitly
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// converted to a std::weak_ptr<const void> and its ownership can be compared with any other std::shared_ptr or
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// std::weak_ptr.
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//
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// The map is initialized with an empty std::weak_ptr mapped to tag 0. This empty entry compares equal to all
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// std::shared_ptr or std::weak_ptr with an empty control block, which is different from having a use_count() == 0,
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// because a std::weak_ptr with a use_count() == 0 can still have an orphaned control block shared with others.
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std::map<std::weak_ptr<const void>, size_t, std::owner_less<void>> shared_ptr_map = { { {}, 0 } };
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// Running owner tag which starts at 1 and increments each time a new std::shared_ptr owner is found
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size_t owner_tag = 1;
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public:
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ser_shared_ptr_packer() = default;
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ser_shared_ptr_packer(const ser_shared_ptr_packer&) = delete;
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ser_shared_ptr_packer& operator=(const ser_shared_ptr_packer&) = delete;
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~ser_shared_ptr_packer() = default;
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// Get the tag associated with a shared pointer's owner, and whether it is new
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std::pair<size_t, bool> get_shared_ptr_owner_tag(const std::weak_ptr<const void>& ptr);
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}; // class ser_shared_ptr_packer
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class ser_shared_ptr_unpacker
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{
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// Array of std::shared_ptr owners indexed by tag.
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//
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// When a std::shared_ptr or std::weak_ptr is deserialized, numeric tags represent different owners.
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//
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// The first time a tag is seen, a std::shared_ptr<PARENT_TYPE> is allocated, and PARENT_TYPE is deserialized.
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//
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// This array keeps an copy of the std::shared_ptr<PARENT_TYPE> owner converted to std::shared_ptr<void> around
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// for every deserialization of std::shared_ptr or std::weak_ptr with the same ownership tag.
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//
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// std::deque is used because it never moves std::shared_ptr around after it is inserted, unlike std::vector.
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std::deque<std::shared_ptr<void>> shared_ptr_owners;
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public:
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ser_shared_ptr_unpacker() = default;
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ser_shared_ptr_unpacker(const ser_shared_ptr_unpacker&) = delete;
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ser_shared_ptr_unpacker& operator=(const ser_shared_ptr_unpacker&) = delete;
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~ser_shared_ptr_unpacker() = default;
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// Get the std::shared_ptr associated with a tag, and whether it is new
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std::pair<std::shared_ptr<void>&, bool> get_shared_ptr_owner(size_t tag);
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}; // class ser_shared_ptr_unpacker
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} // namespace SST::Core::Serialization::pvt
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#endif // SST_CORE_SERIALIZATION_IMPL_SER_SHARED_PTR_TRACKER_H

‎src/sst/core/serialization/impl/serialize_shared_ptr.cc‎

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// Copyright 2009-2025 NTESS. Under the terms
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// of Contract DE-NA0003525 with NTESS, the U.S.
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// Government retains certain rights in this software.
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//
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// Copyright (c) 2009-2025, NTESS
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// All rights reserved.
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//
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// This file is part of the SST software package. For license
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// information, see the LICENSE file in the top level directory of the
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// distribution.
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#include "sst_config.h"
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#include "sst/core/serialization/serialize.h"
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#include <cstddef>
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#include <memory>
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namespace SST::Core::Serialization {
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// Instantiate some templates to make sure all combinations are compilable
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template class serialize_impl<pvt::shared_ptr_wrapper<std::shared_ptr, int, int>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::shared_ptr, int, int[], int>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::shared_ptr, int, int[], size_t>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::shared_ptr, int, size_t>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::shared_ptr, int[], int>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::shared_ptr, int[], int[], int>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::shared_ptr, int[], int[], size_t>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::shared_ptr, int[], size_t>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::weak_ptr, int, int>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::weak_ptr, int, int[], int>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::weak_ptr, int, int[], size_t>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::weak_ptr, int, size_t>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::weak_ptr, int[], int[], int, std::shared_ptr<int[]>>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::weak_ptr, int[], int[], int>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::weak_ptr, int[], int[], size_t, std::shared_ptr<int[]>>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::weak_ptr, int[], int[], size_t>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::shared_ptr, int, int[10], int>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::shared_ptr, int, int[10], size_t>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::shared_ptr, int[10], int>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::shared_ptr, int[10], int[10], int>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::shared_ptr, int[10], int[10], size_t>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::shared_ptr, int[10], size_t>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::weak_ptr, int, int[10], int>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::weak_ptr, int, int[10], size_t>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::weak_ptr, int[10], int[10], int, std::shared_ptr<int[10]>>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::weak_ptr, int[10], int[10], int>>;
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template class serialize_impl<
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pvt::shared_ptr_wrapper<std::weak_ptr, int[10], int[10], size_t, std::shared_ptr<int[10]>>>;
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template class serialize_impl<pvt::shared_ptr_wrapper<std::weak_ptr, int[10], int[10], size_t>>;
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} // namespace SST::Core::Serialization

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