Measuring gives you a leg up on experts who don’t need to measure - Have a good baseline!

see also

• Quick C++ Benchmark - Online tool -
  • found in C++ Weekly - Ep 222 - 3.5x Faster Standard Containers With PMR!

Framework

• facebook/folly
• google/benchmark
  • tutorial

Unpexpected impact on performance

Adding unrelated function slow down/or accelerate code.

• Performance Analysis & Tuning on Modern CPU - Denis Bakhvalov.
  • Blog
  • slides
• Deoptimizing a C++ program