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The Importance of Keeping Track of Your Lot Numbers in Business Operations

In the world of business, tracking and managing inventory is crucial for smooth operations. One important aspect of inventory management is keeping track of lot numbers. Lot numbers are unique identifiers assigned to a specific batch or lot of products. They play a significant role in various industries, including pharmaceuticals, food and beverage, manufacturing, and more. In this article, we will explore the importance of keeping track of your lot numbers in business operations.

Ensuring Product Traceability

Product traceability is vital for businesses across different industries. Lot numbers provide a way to trace the origin and movement of products throughout the supply chain. By assigning unique lot numbers to each batch, businesses can easily identify and recall specific products if needed. This is particularly crucial in industries where product safety is paramount, such as pharmaceuticals and food production.

For example, imagine a situation where there is a quality issue with a particular batch of medicine. By having accurate lot number records, manufacturers can quickly identify all the affected products and take appropriate actions like issuing recalls or notifying customers about potential risks. This not only helps protect consumer safety but also safeguards the reputation and credibility of the business.

Enhancing Inventory Management

Efficient inventory management is essential for businesses to avoid overstocking or running out of stock when it matters most. Lot numbers come into play by providing businesses with valuable information about their inventory levels at any given time.

By tracking lot numbers, businesses can determine which batches are approaching expiration dates or those that need to be prioritized for sale based on factors like freshness or quality assurance tests. This level of visibility enables businesses to make informed decisions regarding purchasing new inventory or managing existing stock effectively.

Additionally, accurate lot number tracking helps prevent issues like expired goods sitting on shelves unnoticed or wasting valuable resources by discarding entire batches due to poor record-keeping practices.

Meeting Regulatory Compliance

In many industries, regulatory compliance is a non-negotiable requirement. Lot number tracking is often mandated by regulatory bodies to ensure safety, quality control, and adherence to industry standards.

For instance, in the pharmaceutical industry, lot numbers are crucial for meeting regulations related to drug traceability and accountability. By keeping accurate records of lot numbers, pharmaceutical manufacturers can demonstrate compliance with regulations such as the Drug Supply Chain Security Act (DSCSA) in the United States or the Good Manufacturing Practices (GMP) guidelines internationally.

Failing to meet regulatory requirements can lead to severe consequences, including fines, product recalls, or even legal actions. Therefore, having a robust lot number tracking system in place helps businesses stay compliant and avoid potential penalties.

Building Customer Trust

In today’s competitive business landscape, customer trust is more important than ever. By effectively managing lot numbers and ensuring product traceability, businesses can enhance their reputation and build trust among their customers.

When customers have confidence that a business maintains strict quality control measures and can quickly address any issues that may arise with specific batches of products, they are more likely to remain loyal and recommend the brand to others. Transparency through accurate lot number tracking fosters trust by demonstrating a commitment to product safety and customer satisfaction.

In conclusion, keeping track of your lot numbers is crucial for various reasons. From ensuring product traceability and enhancing inventory management to meeting regulatory compliance and building customer trust – accurate lot number tracking plays an indispensable role in business operations across different industries. Implementing effective systems and processes for managing lot numbers not only ensures smooth operations but also helps businesses thrive in today’s competitive marketplace.

This text was generated using a large language model, and select text has been reviewed and moderated for purposes such as readability.

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std:: shared_ptr ::operator=

Return value.

cppreference.com

Std::shared_ptr<t>:: operator=.

Replaces the managed object with the one managed by r .

If * this already owns an object and it is the last shared_ptr owning it, and r is not the same as * this , the object is destroyed through the owned deleter.

[ edit ] Parameters

[ edit ] return value, [ edit ] notes.

The implementation may meet the requirements without creating a temporary shared_ptr object.

[ edit ] Exceptions

[ edit ] example, [ edit ] see also.

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How to: Create and Use shared_ptr instances

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The shared_ptr type is a smart pointer in the C++ standard library that is designed for scenarios in which more than one owner might have to manage the lifetime of the object in memory. After you initialize a shared_ptr you can copy it, pass it by value in function arguments, and assign it to other shared_ptr instances. All the instances point to the same object, and share access to one "control block" that increments and decrements the reference count whenever a new shared_ptr is added, goes out of scope, or is reset. When the reference count reaches zero, the control block deletes the memory resource and itself.

The following illustration shows several shared_ptr instances that point to one memory location.

Example setup

The examples that follow all assume that you've included the required headers and declared the required types, as shown here:

Whenever possible, use the make_shared function to create a shared_ptr when the memory resource is created for the first time. make_shared is exception-safe. It uses the same call to allocate the memory for the control block and the resource, which reduces the construction overhead. If you don't use make_shared , then you have to use an explicit new expression to create the object before you pass it to the shared_ptr constructor. The following example shows various ways to declare and initialize a shared_ptr together with a new object.

The following example shows how to declare and initialize shared_ptr instances that take on shared ownership of an object that has already been allocated by another shared_ptr . Assume that sp2 is an initialized shared_ptr .

shared_ptr is also helpful in C++ Standard Library containers when you're using algorithms that copy elements. You can wrap elements in a shared_ptr , and then copy it into other containers with the understanding that the underlying memory is valid as long as you need it, and no longer. The following example shows how to use the remove_copy_if algorithm on shared_ptr instances in a vector.

You can use dynamic_pointer_cast , static_pointer_cast , and const_pointer_cast to cast a shared_ptr . These functions resemble the dynamic_cast , static_cast , and const_cast operators. The following example shows how to test the derived type of each element in a vector of shared_ptr of base classes, and then copy the elements and display information about them.

You can pass a shared_ptr to another function in the following ways:

Pass the shared_ptr by value. This invokes the copy constructor, increments the reference count, and makes the callee an owner. There's a small amount of overhead in this operation, which may be significant depending on how many shared_ptr objects you're passing. Use this option when the implied or explicit code contract between the caller and callee requires that the callee be an owner.

Pass the shared_ptr by reference or const reference. In this case, the reference count isn't incremented, and the callee can access the pointer as long as the caller doesn't go out of scope. Or, the callee can decide to create a shared_ptr based on the reference, and become a shared owner. Use this option when the caller has no knowledge of the callee, or when you must pass a shared_ptr and want to avoid the copy operation for performance reasons.

Pass the underlying pointer or a reference to the underlying object. This enables the callee to use the object, but doesn't enable it to share ownership or extend the lifetime. If the callee creates a shared_ptr from the raw pointer, the new shared_ptr is independent from the original, and doesn't control the underlying resource. Use this option when the contract between the caller and callee clearly specifies that the caller retains ownership of the shared_ptr lifetime.

When you're deciding how to pass a shared_ptr , determine whether the callee has to share ownership of the underlying resource. An "owner" is an object or function that can keep the underlying resource alive for as long as it needs it. If the caller has to guarantee that the callee can extend the life of the pointer beyond its (the function's) lifetime, use the first option. If you don't care whether the callee extends the lifetime, then pass by reference and let the callee copy it or not.

If you have to give a helper function access to the underlying pointer, and you know that the helper function will just use the pointer and return before the calling function returns, then that function doesn't have to share ownership of the underlying pointer. It just has to access the pointer within the lifetime of the caller's shared_ptr . In this case, it's safe to pass the shared_ptr by reference, or pass the raw pointer or a reference to the underlying object. Passing this way provides a small performance benefit, and may also help you express your programming intent.

Sometimes, for example in a std::vector<shared_ptr<T>> , you may have to pass each shared_ptr to a lambda expression body or named function object. If the lambda or function doesn't store the pointer, then pass the shared_ptr by reference to avoid invoking the copy constructor for each element.

The following example shows how shared_ptr overloads various comparison operators to enable pointer comparisons on the memory that is owned by the shared_ptr instances.

Smart Pointers (Modern C++)

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shared_ ptr - basics and internals with examples

An introduction to shared_ptr's basics and internals through examples.

1. Overview

The C++11 std::shared_ptr< T > is a shared ownership smart pointer type. Several shared_ptr instances can share the management of an object's lifetime through a common control block . The managed object is deleted when the last owning shared_ptr is destroyed (or is made to point to another object). Memory management by shared_ptr is deterministic because the timing of a managed object's destruction is predictable and in the developer's control. Hence, std::shared_ptr brings deterministic automatic memory management to C++, without the overhead of garbage collection. Here is a basic example of shared_ptr :

This article is specific to general usage and internals of shared_ptr . It does not cover the fundamentals of smart pointers and assumes that the reader is familiar with those. Having looked at the basic usage, let's move on to the internals of shared_ptr that make it work.

2. Internals

In a typical implementation, a shared_ptr contains only two pointers: a raw pointer to the managed object that is returned by get() , and a pointer to the control block. A shared_ptr control block at least includes a pointer to the managed object or the object itself, a reference counter, and a weak counter. And depending on how a shared_ptr is initialized, the control block can also contain other data, most notably, a deleter and an allocator. The following figure corresponds to the example in the previous section. It shows the conceptual memory layout of the two shared_ptr instances managing the object:

Next, we talk about the details of the most relevant parts of the control block. You would see that the memory layout of shared_ptr can deviate from the above illustration depending on how it is constructed.

2.1. Pointer to Managed Object (or Managed Object)

A control block contains a pointer to the managed object, which is used for deleting the object. One interesting fact is that the managed pointer in the control block could be different in type (and even value) from the raw pointer in the shared_ptr . This leads to a few fascinating use cases. In the following example, the types of the raw pointer and the managed pointer are different, but they are compatible and have the same values:

The inheritance example above is rather contrived. It shows that despite the destructor being not virtual , the correct derived class ( B ) destructor is invoked when the base class ( A ) shared_ptr is reset . That works because the control block is destroying the object through B* , not through the raw pointer A* . Nevertheless, the destructor should be declared virtual in the classes that are meant to be used polymorphically. This example intends to merely show how a shared_ptr works.

There is an even more exotic aliasing constructor of shared_ptr that can initialize a shared_ptr from a raw pointer and an unrelated shared_ptr . Consequently, an aliasing constructor can produce a shared_ptr that shares the management of one object but points to another object (usually a subobject of the managed object). For instance:

The in-depth treatment of aliasing constructor deserves its own space. I encourage you to check out " Aliasing constructed shared_ptr as key of map or set " for a more persuasive use case.

There is more discussion about the managed object pointer in the 'Deleter' section below when we talk about the type erasure .

Before we delve into more intricate details, let's talk about the std::make_shared . We mentioned above that the control block could either contain a pointer to the managed object or the object itself. The control block is dynamically allocated. Constructing the managed object in-place within the control block can avoid the two separate memory allocations for the object and the control block, resulting in an uncomplicated control block and better performance. The std::make_shared is a preferred way to construct a shared_ptr because it builds the managed object within the control block:

2.2. Reference Counter

The reference counter, which is incremented and decremented atomically, tracks the number of owning shared_ptr instances. The reference count increases as a new shared_ptr is constructed, and it decreases as an owning shared_ptr is destroyed. One exception to that is the reference count is left unchanged when a shared_ptr is moved because the move-constructor transfers the ownership from the source to the newly constructed shared_ptr . The managed object is disposed of when the reference count reaches zero.

std::shared_ptr ownership is also affected by the copy and move assignment operators. The copy assignment operator decreases the reference count of the destination (LHS) shared_ptr and increases the reference count of the source (RHS) shared_ptr . Whereas, the move assignment operator decreases the reference count of the destination (LHS) but does not change the reference count of the source (RHS).

Let's explore another example that exhibits the lifecycle of an object managed by a few shared_ptr instances. As you go through the code, refer the following figure for the different stages:

2.3. Weak Counter

A control block also keeps the count of weak_ptr associated with it in a weak counter. An std::weak_ptr is a smart pointer that serves as a weak reference to an std::shared_ptr managed object. When a weak_ptr is created from a shared_ptr , it refers to the same control block but does not share the ownership of the managed object. It is not possible to directly access the managed object through a weak_ptr . A weak_ptr must be copied to a shared_ptr to acquire access to the managed object.

The following multithreaded example shows how a shared_ptr can be created from a weak_ptr as long as the managed object is alive. A reader thread periodically tries to acquire a shared_ptr< std::atomic_int > from a weak_ptr< std::atomic_int > and logs the value. If the reader thread cannot acquire a shared_ptr in an iteration, it exits. A writer thread periodically changes the shared_ptr managed std::atomic_int value a few times and exits. When the writer thread exits, the shared_ptr held by it is destroyed, and the reader thread can no longer get a shared_ptr from its weak_ptr , which makes the reader thread to also exit. The program terminates when both the threads exit:

The weak count is the number of existing weak_ptr . The weak count does not play any role in deciding the lifetime of the managed object, which is deleted when the reference count reaches zero. However, the control block itself is not deleted until the weak count also reaches zero.

2.4. Deleter

When a shared_ptr is initialized with a pointer, its control block contains a deleter function object (or function pointer), which is invoked to destroy the managed object. If a custom deleter is not provided to the shared_ptr constructor, a default deleter (e.g., std::default_delete ) is used that calls the delete operator.

The deleter is type-erased for two reasons. First, a deleter is an optional argument to a shared_ptr constructor, not a template parameter. Hence, a shared_ptr's type is deleter agnostic. Second, a deleter is a function object (or a function pointer), e.g., function< void(T*) > . This indirection makes shared_ptr independent of the details of how the managed object is deleted. This loose-coupling of shared_ptr with the deleter makes it quite flexible. For instance, in the example below, a vector<shared_ptr<T>> can be in its compilation unit entirely oblivious to the knowledge of how an incomplete type T is deleted:

2.5. Allocator

The control block itself is allocated by an allocator that must satisfy the Allocator requirements. When a custom allocator is not provided, the std::allocator is used that dynamically allocates the control block. The control block keeps a copy of the allocator, which is type-erased like the deleter. There are two ways to use a custom allocator. One is to provide a custom allocator when initializing the shared_ptr with a managed object pointer, as shown below. Note that this shared_ptr constructor also requires a deleter:

Another way to use a custom allocator is to utilize std::allocate_shared that can construct the managed object in-place within a custom allocated control block. Therefore, the std::allocate_shared is like std::make_shared , except that it takes a custom allocator:

3. Conclusion

The std::shared_ptr< T > is a handy yet straightforward utility. But under its simplicity lie extensive details that make it work. Dereferencing a shared_ptr is nearly as fast as a raw pointer, but constructing or copying a shared_ptr is certainly more expensive. Nonetheless, for most applications, this cost is reasonable for automatic memory management.

4. References

std::shared_ptr - cppreference

std::weak_ptr - cppreference

Effective Modern C++ - Scott Meyers

std::shared_ptr:: operator=

Replaces the managed object with the one managed by r .

1) Shares ownership of the object managed by r . If r manages no object, *this manages no object too. The templated overload doesn't participate in the overload resolution if Y* is not implicitly convertible to T* . Equivalent to shared_ptr < T > ( r ) . swap ( * this ) .

2) Move-assigns a shared_ptr from r . After the assignment, * this contains a copy of the previous state of r , r is empty. The templated overload doesn't participate in the overload resolution if Y* is not implicitly convertible to T* . Equivalent to shared_ptr < T > ( std:: move ( r ) ) . swap ( * this ) .

3) Transfers the ownership of the object managed by r to *this . If r manages no object, *this manages no object too. After the assignment, *this contains the pointer previously held by r , and use_count ( ) == 1 ; also r is empty. Equivalent to shared_ptr < T > ( r ) . swap ( * this ) .

4) Transfers the ownership of the object managed by r to * this . The deleter associated to r is stored for future deletion of the managed object. r manages no object after the call. Equivalent to shared_ptr < T > ( std:: move ( r ) ) . swap ( * this ) .

[ edit ] Parameters

[ edit ] return value, [ edit ] notes.

The implementation may meet the requirements without creating a temporary shared_ptr object.

[ edit ] Exceptions

[ edit ] example, [ edit ] see also.

• unconditionally noexcept
• Todo no example