binary stream with std::stringstream problem

[akitoto]

Hi there,

I am using the std::stringstream to create a byte array in memory. But
it is not working properly. Can anyone help me?

Code:

#include <vector>
#include <sstream>
#include <iostream.h>

int main(int argc, char* argv[])
{
std::vector<doublevector (2, 12.3456);
std::stringstream stream
(std::stringstream::out|std::stringstream::binary) ;

unsigned int sz = vector.size();
stream << sz;
for (unsigned int i = 0; i < sz; i++)
{
stream << vector[i];
}

//results
std::string buffer = stream.str();
cout << buffer.c_str() << endl;

return 0;
}

output:
212.345612.3456

Why is the output not some byte-sequence, but formatted text?

[Ondra Holub]

[e-mail] napsal:

Hi there,

I am using the std::stringstream to create a byte array in memory. But
it is not working properly. Can anyone help me?

Code:

#include <vector>
#include <sstream>
#include <iostream.h>

int main(int argc, char* argv[])
{
std::vector<doublevector (2, 12.3456);
std::stringstream stream
(std::stringstream::out|std::stringstream::binary) ;

unsigned int sz = vector.size();
stream << sz;
for (unsigned int i = 0; i < sz; i++)
{
stream << vector[i];
}

//results
std::string buffer = stream.str();
cout << buffer.c_str() << endl;

return 0;
}

output:
212.345612.3456

Why is the output not some byte-sequence, but formatted text?

Which output do you expect? it is correct, because first you are
writing to output length of vector (which is 2) and then you dump all
vector items without delimiters (both items are 12.3456).

Btw. your source is not correct, there is used #include <iostream.h>
(but should be <iostream>) and there are missing some std:: prefixes.

[Ondra Holub]

ak*****@gmail.com napsal:

Hi there,

I am using the std::stringstream to create a byte array in memory. But
it is not working properly. Can anyone help me?

Code:

#include <vector>
#include <sstream>
#include <iostream.h>

int main(int argc, char* argv[])
{
std::vector<doublevector (2, 12.3456);
std::stringstream stream
(std::stringstream::out|std::stringstream::binary) ;

unsigned int sz = vector.size();
stream << sz;
for (unsigned int i = 0; i < sz; i++)
{
stream << vector[i];
}

//results
std::string buffer = stream.str();
cout << buffer.c_str() << endl;

return 0;
}

output:
212.345612.3456

Why is the output not some byte-sequence, but formatted text?

I see, you want binary output. You cannot use operator<< for binary
output. Use method 'write' of stream.

Btw, in 99% is writing binary output not good idea (for
interoperability and portability reasons).