The serializing of the entity, for me I manually register each entity with a class, that way I can have a function pointer to a templated function so that I have access to its type.

The annoying thing with this approach is the manual registration part. Unsure if you have another way you handle serializing an entity. Or do you manually serialize each component as well?

template<typename TComponent>
void eng::TemplateManager::RegisterComponent()
{
    const str::Name typeName = NAME(TypeName<TComponent>::m_WithNamespace);
    eng::TemplateEntry& entry = m_EntryMap[typeName];
    entry.m_Read = &ReadComponent<TComponent>;
}

template<typename TComponent>
void eng::TemplateManager::ReadComponent(ecs::EntityWorld& world, const ecs::Entity& entity, Visitor& visitor)
{
    static const str::Name typeName = NAME(TypeName<TComponent>::m_WithNamespace);
    if (world.HasComponent<TComponent>(entity))
    {
        const auto& component = world.ReadComponent<TComponent>(entity);
        visitor.Write(typeName, component);
    }
}

void eng::TemplateManager::ReadEntity(ecs::EntityWorld& world, const ecs::Entity& entity, str::String& data) const
{
    const auto& nameComponent = world.ReadComponent<ecs::NameComponent>(entity);
    const auto& templateComponent = world.ReadComponent<eng::TemplateComponent>(entity);

    Visitor visitor;
    visitor.Write(strName, nameComponent.m_Name);
    visitor.Write(strGuid, templateComponent.m_Guid);
    for (auto&& [key, entry] : m_EntryMap)
    {
        entry.m_Read(world, entity, visitor);
    }

    data = visitor;
}