Invisible streaming?

[Poldanziern]

Is there such a thing in C++ as stream which you can pass data into
and then retrieve data out of on the other end (without interacting
with the user or a file)?

For example, I'd like to extract a bunch of numbers, separated by
whitespace from a string ... say for example:

mystring = "100 2.0 666 3.14";

I realize that if the string contained only one number, I could use
atoi(). If it was reading in from a file, I could use myfilestream >>
a >> b >> c >> d;.

So basically I'm wondering if there's such a thing as a type of stream
object such that I could feed such a string into on one end and then
extract the variables out of the other end.

Like this:

stream mystream;
mystream << mystring;
mystream >> a >> b >> c >> d;

I know I could achieve this by streaming it out to a file and then
streaming it back in; I just want to know if there's a way to skip the
middle stage.

-Keith

[Jerry Coffin]

In article <fe********************************@4ax.com>, [e-mail] says...

Is there such a thing in C++ as stream which you can pass data into
and then retrieve data out of on the other end (without interacting
with the user or a file)?

From your description, you want to look up std::stringstream.

--
Later,
Jerry.

The universe is a figment of its own imagination.

[Andre Kostur]

Poldanziern <[e-mail]> wrote in news:fepeovcjgo8lg5cr2tl2k6n7qd95qiav99@
4ax.com:

Is there such a thing in C++ as stream which you can pass data into
and then retrieve data out of on the other end (without interacting
with the user or a file)?

For example, I'd like to extract a bunch of numbers, separated by
whitespace from a string ... say for example:

mystring = "100 2.0 666 3.14";

I realize that if the string contained only one number, I could use
atoi(). If it was reading in from a file, I could use myfilestream >>
a >> b >> c >> d;.

So basically I'm wondering if there's such a thing as a type of stream
object such that I could feed such a string into on one end and then
extract the variables out of the other end.

Like this:

stream mystream;
mystream << mystring;
mystream >> a >> b >> c >> d;

I know I could achieve this by streaming it out to a file and then
streaming it back in; I just want to know if there's a way to skip the
middle stage.

Close....

#include <sstream>
#include <string>

std::string mystring = "100 2.0 666 3.14";
std::istringstream mystream(mystring.c_str());

mystream >> a >> b >> c >> d;
(OK... assuming that a-d are appropriately typed....)

[Poldanziern]

On Sat, 11 Oct 2003 02:39:35 GMT, Jerry Coffin <jc*****@taeus.com>
wrote:

In article <fe********************************@4ax.com>, [e-mail] says...

Is there such a thing in C++ as stream which you can pass data into
and then retrieve data out of on the other end (without interacting
with the user or a file)?

From your description, you want to look up std::stringstream.

From a preliminary Google search, I believe that is exactly what I was
looking for. Thanks!

-Keith

[Rolf Magnus]

Andre Kostur wrote:

Poldanziern <[e-mail]> wrote in
news:fepeovcjgo8lg5cr2tl2k6n7qd95qiav99@ 4ax.com:

Is there such a thing in C++ as stream which you can pass data into
and then retrieve data out of on the other end (without interacting
with the user or a file)?

For example, I'd like to extract a bunch of numbers, separated by
whitespace from a string ... say for example:

mystring = "100 2.0 666 3.14";

I realize that if the string contained only one number, I could use
atoi(). If it was reading in from a file, I could use myfilestream

>> a >> b >> c >> d;.
So basically I'm wondering if there's such a thing as a type of
stream object such that I could feed such a string into on one end
and then extract the variables out of the other end.

Like this:

stream mystream;
mystream << mystring;
mystream >> a >> b >> c >> d;

I know I could achieve this by streaming it out to a file and then
streaming it back in; I just want to know if there's a way to skip
the middle stage.

Close....

#include <sstream>
#include <string>

std::string mystring = "100 2.0 666 3.14";
std::istringstream mystream(mystring.c_str());

That constructor wants a string, not a pointer to char.
mystream >> a >> b >> c >> d;
(OK... assuming that a-d are appropriately typed....)