The Many Faces of Number ⟷ String Conversions

Dvir Yitzchaki

online
90 minute session
beginner
intermediate
18:00-19:30, Thursday, 14th July 2022

Seemingly a basic task, converting between numbers and their string representation is a problem which has kept C++ busy since its birth.

C++ inherited several library functions from C dealing with such conversions and has kept adding more on almost every new standard, the latest examples being to/from_chars from C++17 and C++20’s format library. This didn’t stop non-standard libraries, like Boost, from offering even more ways to do those conversions.

In this talk we will explore

  • std::atoi
  • std::stoi
  • std::to_string
  • std::from_chars
  • boost::lexical_cast
  • std::scan

and more. We will try to understand why the number-string conversion problem is being solved repeatedly, compare the API, implementation and performance of these utilities and see that, even now, there still room for improvement.

API
performance
STL
Boost

Dvir Yitzchaki

A senior software engineer at Yahoo/Edgecast, a conference speaker and a member of the Israeli National Body for C++ standardization.