I once worked for a startup that had a custom C++ basic library for strings, arrays, smart pointers and things like that. At some point I spent the better part

I once worked for a startup that had a custom C++ basic library for strings, arrays, smart pointers and things like that. At some point I spent the better part of a week looking into a bug that, long story short, was caused by a bug in our custom String class. Please don't do this. Every line of code in your project that your team maintains is a liability.