I have a function that use std::istream as parameter. Right now I need
to pass a std::string into it, how can I convert std::string to
std::istream type?

Thanks

Water Lin

-- 
Water Lin's notes and pencils: http://en.waterlin.org
Email: WaterLin@ymail.com

Water Lin wrote:
> I have a function that use std::istream as parameter. Right now I need
> to pass a std::string into it, how can I convert std::string to
> std::istream type?

You can't directly, but you can use a stringstream:

#include <iostream>
#include <sstream>

void f( std::istream& in )
{
   std::string s;
   in >> s;
   std::cout << s << std::endl;
}

int main()
{
   std::string s("hello");
   std::istringstream ss( s );

   f( ss );
}

-- 
Ian Collins

Ian Collins <ian-news@hotmail.com> writes:

> Water Lin wrote:
>> I have a function that use std::istream as parameter. Right now I need
>> to pass a std::string into it, how can I convert std::string to
>> std::istream type?
>
> You can't directly, but you can use a stringstream:
>
> #include <iostream>
> #include <sstream>
>
> void f( std::istream& in )
> {
>   std::string s;
>   in >> s;
>   std::cout << s << std::endl;
> }
>
> int main()
> {
>   std::string s("hello");
>   std::istringstream ss( s );
>
>   f( ss );
> }


Thanks, I got it.

Water Lin

-- 
Water Lin's notes and pencils: http://en.waterlin.org
Email: WaterLin@ymail.com

Ian Collins wrote:
> Water Lin wrote:
>> I have a function that use std::istream as parameter. Right now I need
>> to pass a std::string into it, how can I convert std::string to
>> std::istream type?
> 
> You can't directly, but you can use a stringstream:

  Maybe I'm being hugely pedantic here, but what do you mean "you can't
directly"? How is giving the string to a strinstream *not* converting
the string to a std::istream? To me it sounds like being exactly that.