How Does `std::vector` Handle Dynamic Array Reallocation in C ?

Reallocation in C : Exploring the std::vector Solution

In C , the absence of an explicit realloc function might raise concerns when you need to expand dynamic buffers. However, the std::vector template class provides a convenient and efficient solution to this problem.

Understanding Reallocation

Reallocation involves adjusting the size of a previously allocated memory block. In C , this is achieved through the realloc function. However, C introduces the std::vector class, which manages dynamic arrays and offers a simpler and safer method for reallocation.

Using std::vector for Reallocation

To allocate an array of n elements with initial values set to 0, you would typically use:

Type* t = (Type*)malloc(sizeof(Type)*n);
memset(t, 0, sizeof(Type)*m);

With std::vector, this can be simplified to:

std::vector<Type> t(n, 0);

To enlarge the array to accommodate n2 elements, you would use:

t = (Type*)realloc(t, sizeof(Type) * n2);

With std::vector, this is achieved by:

t.resize(n2);

Passing Pointers to Functions

When passing pointers to functions, you can use &t[0] instead of t. This is valid because std::vector supports the use of its elements as pointers to the underlying array.

Foo(&t[0])

Conclusion

By utilizing std::vector, you can easily and securely reallocate dynamic memory in C . This eliminates the need for explicit memory management, making your code more concise and less error-prone.

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