C++ Standard Template Library in Practice - Defining an Allocator

The video tutorial covers the basics of custom allocators in C++, explaining their roles in memory management, including allocation, construction, destruction, and deallocation. It details how to define a minimal allocator and explores allocator behaviors and flags introduced in C++17. The tutorial provides a practical example by creating a debug allocator, demonstrating its implementation and testing it with a vector to observe memory allocation and deallocation processes.

What are the four main functions of an allocator?

• Allocate, create, remove, deallocate

• Allocate, build, destroy, release

• Allocate, initialize, finalize, deallocate

• Allocate, construct, destruct, deallocate

What is the purpose of the 'is always equal' flag in allocators?

• To make allocators immutable

• To prevent allocators from being copied

• To allow different instances of the same allocator type to manage each other's memory

• To ensure all allocators are identical

What is the significance of the 'propagate on container swap' flag?

• It prevents memory leaks during swaps

• It ensures allocators are not swapped

• It optimizes swap operations

• It determines if allocators should be swapped with elements

In the example of creating a debug allocator, what is the role of the allocate function?

• To log memory usage

• To release memory back to the system

• To construct an object in memory

• To acquire raw memory and return a pointer

What does the construct function in a debug allocator do?

• It logs the memory address

• It releases memory back to the system

• It constructs an object at a specific memory location

• It initializes memory with zeros

When using a debug allocator with a vector, what happens when the vector exceeds its current capacity?

• The vector stops accepting new elements

• The vector reallocates a larger block of memory

• The vector throws an exception

• The vector compresses its elements

How does the debug allocator help in understanding memory usage in standard containers?

• By reducing memory fragmentation

• By optimizing memory usage

• By logging memory allocation and deallocation

• By preventing memory leaks