std::stringstream && std::string

[KidLogik]

Hello!

I am using std::stringstream && std::string to parse a text file ->

std::ifstream in;
std::string s;
std::streamstring ss;
int n;

I grab each line like so -> std::getline(in,s);

I then do this to get the string into a stringstream -> ss << s;

I am using a std::stringstream because it makes extracting data easier
like so -> ss >> n;

Is this the proper way to use std::stringstream? How do I blank out
the std::stringstream object because each time I do a (ss << s the
stream keeps concatenating onto itself...how do I blank out the stream
to add a new string to it?

Thanks.

 

[Ivan Vecerina]

Hi,

I am using std::stringstream && std::string to parse a text file ->

std::ifstream in;
std::string s;
std::streamstring ss;

You mean stringstream I guess (and istringstream would actually be
best, once you follow the approach below).

int n;

I grab each line like so -> std::getline(in,s);

I then do this to get the string into a stringstream -> ss << s;

What you really want to do is either:
- use the str(s) member function: ss.str(s); // resets buffer to s
- re-create a new istringstream instance for every line:
std::istringstream ss(s);
(the latter will eventually be less efficient on some platforms).


Regards,
Ivan

 

[Alberto Barbati]

What you really want to do is either:
- use the str(s) member function: ss.str(s); // resets buffer to s

By using ss.str(s) you don't even need to use "ss << s;" and it should
also be more efficient. In that case you don't need to use a
stringstream, an istringstream is sufficient.

Regards,

Alberto