Seulgi Kim

RAII is a frequently used idiom in C++ that ensures the safe usage of resources by releasing them when an object's scope ends. In C++, resources allocated on the heap are not released unless explicitly done so, but those allocated on the stack are automatically released when their scope ends, triggering their destructor. Originally, RAII was used to guard against unexpected changes in control flow, such as exceptions. In the above code example, the unsafeFunction() function is not safe. If the thisFunctionCanThrowException() throws an exception, the resource may not be released. The unmaintanableFunction releases the resource , but it is not easy to read and maintain. The safeFunction example uses unique_ptr , a smart pointer introduced at C++11, for RAII. unique_ptr automatically releases the memory it holds when it is destroyed, ensuring that the resource is released when the function exits. The resource does not only refer to heap memory but also includes files, d...

Garbage collection is a technique that automatically releases unnecessary memory. It's very famous because many programming languages adopted garbage collection after John McCarthy implemented it in Lisp. However, there are a few people who misunderstand what garbage collection does. If you think garbage collection prevents a memory leak, unfortunately, you are one of them. Garbage collection cannot prevent a memory leak. There is no way to avoid all memory leaks if you are using Turing-complete language. To understand it you should know what a memory leak is. Wikipedia describes a memory leak as the following: a type of resource leak that occurs when a computer program incorrectly manages memory allocations in such a way that memory which is no longer needed is not released. Briefly, a memory leak is a bug that doesn't release a memory that you don't use. So it is first to find the memory which will not be used in order to detect memory leaks. Unfortunately, it i...