Home/ Questions/Q 34831
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-10T14:08:25+00:00

For data types such as std::set and std::map where lookup occurs in logarithmic time,

  • 0

For data types such as std::set and std::map where lookup occurs in logarithmic time, is the implementation required to maintain the begin and end iterators? Does accessing begin and end imply a lookup that could occur in logarithmic time?

I have always assumed that begin and end always occur in constant time, however I can’t find any confirmation of this in Josuttis. Now that I’m working on something where I need to be anal about performance, I want to make sure to cover my bases.

Thanks

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. They happen in constant time. I’m looking at page 466 of the ISO/IEC 14882:2003 standard:

    Table 65 – Container Requiments

    a.begin(); (constant complexity)

    a.end(); (constant complexity)

    Table 66 – Reversible Container Requirements

    a.rbegin(); (constant complexity)

    a.rend(); (constant complexity)

    • 0