At pretty much every game studio there is an epic internal battle of standard libs vs custom. std::string and [some custom string class] here it is AString is usually the spark. A constant of internal game development is that they think they can always build better strings, lists, dictionaries, collections etc than the standard lib, basically thinking the standard lib is as it was in the 90s and all the work that went into them is bunk. In some cases if you are really pushing memory and not writing custom allocators or using something like boost then yes, but in most cases the technical debt of custom classes written by an ancient from generations ago internally is more technical debt.

> One of the best examples of MacGyver debt in the LoL codebase is the use of C++’s std::string vs. our custom AString class. Both are ways to store, modify, and pass around strings of characters. In general, we’ve found that std::string leads to lots of “hidden” memory allocations and performance costs, and makes it easy to write code that does bad things. AString is specifically designed with thoughtful memory management in mind. Our strategy for replacing std::string with AString was to allow both to exist in the codebase and provide conversions between the two (via .c_str() and .Get() respectively). We gave AString a number of ease-of-use improvements that make it easier to work with and encouraged engineers to replace std::string at their leisure as they change code. Thus, we’re slowly phasing std::string out and the “duct tape” interface between the two systems slowly shrinks as we tidy up more of our code.

So now there are two string classes, that is technical debt... and one should be consolidated on and the arguments against std::string are sometimes valid but you can also do custom memory allocators or use better standard lib iterations.

EA even rewrote the whole standard lib EASTL [1] to adjust for some of these issues i.e. fragmented memory. Some games require it, some it is pure ego in game development teams. Game development teams have the highest ego driven development (EDD) I have ever seen and lots of tricks that take five minutes (but add 2-3 months to testing due to five minute solutions) but are more spaghetti than templates that write templates.

The one problem that comes about with your own standard lib or thinking you are better than boost or similar, is that the learning curve on the internal lib replacements add technical debt and start up costs, and the original guy that wrote them is long gone usually. Also, in the end portability suffers as there is invariably 3-4 versions of the internal libs.

Developers have to weigh the technical debt of your own custom classes outside standard libs and see if that outweighs the memory issues that may arise. Today most machines are not as affected by memory fragmentation issues and there is more cpu/memory to go around, and where they are you can write custom allocators for std/stl or use something like boost.

I do love Riot Games and all game development teams just I have never worked in one or with one that doesn't have the standard lib vs custom battle and wastes lots of time when one isn't standardized on or when not necessary. Some games and game engines require it, where they do you should fully commit one way or the other. Though going custom leads to slowdowns in coding for new devs and invariably there will be multiple versions of those internal libs over time that add up in the debt department.

[1] https://github.com/electronicarts/EASTL