std:stringstream reset

[Giampiero Gabbiani]

Is it possible to reset a std::stringstre am in order to reuse it once more?
I tried with flush() method without any success...
Thanks in advance
Giampiero

[WW]

Re: std:stringstrea m reset

Giampiero Gabbiani wrote:[color=blue]
> Is it possible to reset a std::stringstre am in order to reuse it once
> more? I tried with flush() method without any success...[/color]

Have you tried seeking to the beinning?

--
WW aka Attila

[Giampiero Gabbiani]

Re: std:stringstrea m reset

Il Sun, 19 Oct 2003 20:35:21 +0300, WW ha scritto:
[color=blue]
> Giampiero Gabbiani wrote:[color=green]
>> Is it possible to reset a std::stringstre am in order to reuse it once
>> more? I tried with flush() method without any success...[/color]
>
> Have you tried seeking to the beinning?[/color]
Yes, I tried seekp(0), but it continues not to reset the stream.
Actually I use this stream (a std::ostringstr eam) for writing message to
system log, so I use the str() method in order to print the message in the stream.

[Gianni Mariani]

Re: std:stringstrea m reset

Giampiero Gabbiani wrote:[color=blue]
> Is it possible to reset a std::stringstre am in order to reuse it once more?
> I tried with flush() method without any success...
> Thanks in advance
> Giampiero
>[/color]


The "str()" and "str( string )" methods should work.
However, on some platforms these may not work so you
may use the ugly reconstruct hack.


#include <sstream>
#include <iostream>

int main()
{

std::istringstr eam iss( "Hi there" );

std::ostringstr eam oss;

std::string foo;

iss >> foo;
oss << foo;

iss.str( "boo hoo" ); // Set the input to new string

iss >> foo;
oss << foo;
std::cout << oss.str() << "\n";

// Another way is to reconstruct the istringstream
// UGLY but some implementations have bugs and this is the
// only way.
iss.~istringstr eam();
new ( (void *) &iss ) std::istringstr eam( "Reconstruc t this" );

oss.str( "" ); // reset the output string.

iss >> foo;
oss << foo;
std::cout << oss.str() << "\n";

// Another way is to reconstruct the ostringstream
oss.~ostringstr eam();
new ( (void *) &oss ) std::ostringstr eam;

iss >> foo;
oss << foo;
std::cout << oss.str() << "\n";

}

[Ron Natalie]

Re: std:stringstrea m reset


"Giampiero Gabbiani" <giampiero_gabb iani@tin.it> wrote in message news:pan.2003.1 0.19.17.15.26.3 702@tin.it...[color=blue]
> Is it possible to reset a std::stringstre am in order to reuse it once more?
> I tried with flush() method without any success...[/color]

Just set the string via the str(const string&) method (to either an empty string or
one with new data as appropriate for what you are doing).

[Giampiero Gabbiani]

Re: std:stringstrea m reset

Il Sun, 19 Oct 2003 17:40:09 +0000, Gianni Mariani ha scritto:
[color=blue]
> Giampiero Gabbiani wrote:[color=green]
>> Is it possible to reset a std::stringstre am in order to reuse it once more?
>> I tried with flush() method without any success...
>> Thanks in advance
>> Giampiero
>>[/color]
>
>
> The "str()" and "str( string )" methods should work.
> However, on some platforms these may not work so you
> may use the ugly reconstruct hack.
>
>
> #include <sstream>
> #include <iostream>
>
> int main()
> {
>
> std::istringstr eam iss( "Hi there" );
>
> std::ostringstr eam oss;
>
> std::string foo;
>
> iss >> foo;
> oss << foo;
>
> iss.str( "boo hoo" ); // Set the input to new string
>
> iss >> foo;
> oss << foo;
> std::cout << oss.str() << "\n";
>
> // Another way is to reconstruct the istringstream
> // UGLY but some implementations have bugs and this is the
> // only way.
> iss.~istringstr eam();
> new ( (void *) &iss ) std::istringstr eam( "Reconstruc t this" );
>
> oss.str( "" ); // reset the output string.
>
> iss >> foo;
> oss << foo;
> std::cout << oss.str() << "\n";
>
> // Another way is to reconstruct the ostringstream
> oss.~ostringstr eam();
> new ( (void *) &oss ) std::ostringstr eam;
>
> iss >> foo;
> oss << foo;
> std::cout << oss.str() << "\n";
>
> }[/color]
Thanks a lot, I succeeded in resetting the stream with str("") method
call!
Bye
Giampiero

[Giampiero Gabbiani]

Re: std:stringstrea m reset

Il Sun, 19 Oct 2003 13:42:06 -0400, Ron Natalie ha scritto:
[color=blue]
>
> "Giampiero Gabbiani" <giampiero_gabb iani@tin.it> wrote in message news:pan.2003.1 0.19.17.15.26.3 702@tin.it...[color=green]
>> Is it possible to reset a std::stringstre am in order to reuse it once more?
>> I tried with flush() method without any success...[/color]
>
> Just set the string via the str(const string&) method (to either an empty string or
> one with new data as appropriate for what you are doing).[/color]
Thanks a lot, I succeeded in resetting the stream with str("") method
call!
Bye
Giampiero