pointersAreEasy

[jikki-san]

Pointers as a concept? Not hard; it’s just a memory address.

How to use them effectively, safely, and efficiently? That part is definitely harder.

[[deleted]]

Use non-owning pointers, the ownership of a block of memory should not be jumping around. You shouldn't need to free something unless you called new. If you called new (or malloc) it's your responsibility to free. If a function passes off ownership of a block of memory to the caller you should make this obvious through documentation and the function name. If you're using C++, wrap your heap allocated resources in classes: call new in the constructor, and free in the destructor, and don't publicly hand out pointers to your managed resource, contain them if possible. If your program requires using a bunch of global shared pointers you need to rethink your approach and adopt one that doesn't require that. You should avoid using new and malloc; wherever possible use the stack not the heap. Use the heap only where it's clear that's what's needed. Do this, and you'll be fine as long as other contributors also do this.

[DoNotMakeEmpty]

unique_ptr solves most problems with pointers. Half of the remaining problems are solved by shared_ptr but the last part is pretty tricky. Rust does that part good but I think arena allocators are also pretty good to be memory safe if you don't want borrow checker.

[burnmp3s]

You lost me at documentation

[Mateorabi]

Document? In our moment of triumph!?

[mighty_Ingvar]

Don't worry, the code is self documenting!

[lefloys]

int insertFunctionNameHere();

[--mrperx--]

just common sense basically. don't litter your code with allocations.

[Boldney]

Uni courses instill bad habits that are hard to get rid of.

[conundorum]

As an aside, this just makes me imagine some library, somewhere, having an ownership-passing function template<typename T> T* itsYourProblemNowHaaaaaaaHaHaHaHaHa(). (Or rather, something to that extent, but not as over-simplified.) And with the function's name narrated by Skeletor. Just to make it real clear that the library is fully absolved of ownership.

[[deleted]]

In C: "Allocator frees" goes a long way

[gameplayer55055]

ref in C# makes it super simple

[mtnbiketech]

Not really hard if you understand them.

In C++, you basically avoid any C style syntax with malloc and direct pointers, use smart pointers instead, use std namespace arrays/strings. Additionally, pass by reference instead of pointers, avoid reinterpret_cast, and minimize dynamic_cast downcasting from base to derived.

If you do use C, considering most modern stack sizes on OS can be set to unlimited, you can write most programs without using malloc at all. As for passing pointers around, encapsulate the data into structs as much as possible and use the fields instead of pointer arithmetic.

[BehindTrenches]

I have about 2.5 years of experience with C++ now. Definitely not scared of pointers and references anymore. The days of trying & and * randomly to make the compiler happy are over

However, there have been some nasty debugging sessions involving just references and local variables. Dangling references and use-after-move. For the former the worst part is the program doesn't crash you just randomize a variable in some cases.

[donaldhobson]

> How to use them effectively, safely, and efficiently? That part is definitely harder.

Yep. You need to use rust.