Why/when should you use STL?

Code reuse, the code has already been written and tested. Since it’s in the standard, you can expect portability too. You also get guarantees about the performance of particular parts of STL.

• STL aims to do as well as you could if you crafted non-templated code.

• There are improvements over C++98/C++03 performance, particularly related to move (rvalue reference) support.

STL is great if you are doing operations where existing STL algorithms and containers best suit your problem.

• The different containers, we will see soon, provide operations at different costs.

If you aren’t necessarily too concerned about precisely optimising the performance but want your code to follow standard conventions and be portable, STL may be the way to go.

The textbook notes: “Modern C++ programs should use the library containers rather than more primitive structures like arrays.”

• And there is an array replacement too anyway.