std::to_string faster than light

Presentation is a story of a single PR in libc++ LLVM.

A humble attempt to speedup std::to_string of integers has evolved into a whole study of requirements and implementations of numbers formatting in C++.

We will have a look at the initial std::to_string implementation and make suggestions on possible performance improvements.

Three subsequent implementation iterations are considered:

• allocations optimization;
• naive approach;
• std::to_chars.

We will profile each algorithm, discuss results and analyze performance tricks for the fast integers formatting.