c++ boost lexical cast double to string

Question

For the following piece of code

std::cout<<boost::lexical_cast<std::string>(2.34)<<std::endl

i get the following output:

2.3399999999999999

Whereas if i do

 double d = 2.34;
 std::stringstream ss;
 ss<<d;
 std::string s = ss.str();
 cout<<s<<endl;

i get the following output:

 2.34

Why is this happening ? Obviously, I am looking for the latter's output representation, and not the former.

Thanks,

@NicolBolas edited, not sure how that 1 slipped in ... – Aditya Sihag Jul 26 '12 at 08:58 — Aditya Sihag, Jul 26 '12 at 08:58

score 1 · Answer 1 · edited May 23 '17 at 11:44

1

This has nothing to do with the boost::lexical_cast, but it comes along with double's internal representation:

edited May 23 '17 at 11:44

Community

answered Jul 26 '12 at 06:19

sebm

That was my initial instinct, too, but only `double`s are explicitly used here (no `float`s). See http://ideone.com/iVw2e for a demonstration. – johnsyweb Jul 26 '12 at 09:15

1 Answers1