creating output string

[Cleverbum]

Hi,
I've written a class which contains a number of doubles which I would
like to extract as a string in the format:
double tab double tab...
I've tried a whole host of ideas but I'm drawing a blank when it comes
to compile time. my most recent attempt is:

string toString(){
string output = ("%d\t%d\t%d\t%d\t%d\t%d\t", pos[0], pos[1],
pos[2], vel[0],
vel[1], vel[2]) ;
return output ;
}

can anyone help?

[Michiel.Salters]

Cl*******@hotmail.com wrote:

Hi,
I've written a class which contains a number of doubles which I would
like to extract as a string in the format:
double tab double tab...
I've tried a whole host of ideas but I'm drawing a blank when it comes
to compile time.

Try std::ostringstream. It works similar to std::cout, except that the
characters are stored in a string instead of going to the screen.

HTH,
Michiel Salters.

[mlimber]

Cl*******@hotmail.com wrote:

Hi,
I've written a class which contains a number of doubles which I would
like to extract as a string in the format:
double tab double tab...
I've tried a whole host of ideas but I'm drawing a blank when it comes
to compile time. my most recent attempt is:

string toString(){
string output = ("%d\t%d\t%d\t%d\t%d\t%d\t", pos[0], pos[1],
pos[2], vel[0],
vel[1], vel[2]) ;
return output ;
}

can anyone help?

As the FAQ indicates
(http://www.parashift.com/c++-faq-lit...html#faq-39.1),
you can use a std::ostringstream:

std::string toString() const
{
std::ostringstream oss;
oss << pos[0] << '\t' << pos[1] /* etc. */;
return oss.str()
}

Cheers! --M

[Stefan Näwe]

Cl*******@hotmail.com schrieb:

Hi,
I've written a class which contains a number of doubles which I would
like to extract as a string in the format:
double tab double tab...
I've tried a whole host of ideas but I'm drawing a blank when it comes
to compile time. my most recent attempt is:

string toString(){
string output = ("%d\t%d\t%d\t%d\t%d\t%d\t", pos[0], pos[1],
pos[2], vel[0],
vel[1], vel[2]) ;
return output ;
}

can anyone help?

Use a std::stringstream:

std::string toString()
{
std::ostringstream os;
os << pos[0] << '\t'
<< pos[1] << '\t'
<< pos[2] << '\t'
<< vel[0] << '\t'
<< vel[1] << '\t'
<< vel[2] << '\t';
return os.str();
}

HTH
/S
--
Stefan Naewe
naewe.s_AT_atlas_DOT_de

[Cleverbum]

thanks, problem solved

[Cleverbum]

Perhaps I'm being remedial, but this doesnt seem to work, it all looked
so simple, but the compiler throwing a hissy fit. my code now is:

std::string toString(){
std::ostringstream os;
os << pos[0] << '\t'
<< pos[1] << '\t'
<< pos[2] << '\t'
<< vel[0] << '\t'
<< vel[1] << '\t'
<< vel[2] << '\t';
return os.str();
} ;
but the compiler says:

In member function `std::string particle::toString()':
testtwo.cc:56: error: aggregate `std::ostringstream os' has incomplete
type and cannot be defined

what's going on??!!

[cbmanica]

Cl*******@hotmail.com wrote:

In member function `std::string particle::toString()':
testtwo.cc:56: error: aggregate `std::ostringstream os' has incomplete
type and cannot be defined

what's going on??!!

Perhaps you neglected to #include the proper header, which in this case
is <sstream>?

[Cleverbum]

that would be it... maybe this is why i shouldn't stray outside of c++
for dummies just yet.