What is meant by Resource Acquisition is Initialization (RAII)?

Question

What is meant by Resource Acquisition is Initialization (RAII)?

Answer 1

The book C++ Programming with Design Patterns Revealed describes RAII as:

1. Acquiring all resources
2. Using resources
3. Releasing resources

Where

• Resources are implemented as classes, and all pointers have class wrappers around them (making them smart pointers).

• Resources are acquired by invoking their constructors and released implicitly (in reverse order of acquiring) by invoking their destructors.