binary i/o question

[Matt Jackson]

I've developed a templated binary read/write routine:

template<class T>
void write(ofstream& out,T data){
out.write((char*)&data,sizeof(T));
}

template<class T>
void read(ifstream& in,T& data){
in.read((char*)(&data),sizeof(T));
}
Which I call in a function like:

ofstream out;
out.open("restart.solv",ios::out|ios::binary);
write(out,var);
out.close();

ifstream in;
in.open("restart.solv",ios::in|ios::binary);
read(in,var);

Where var is a double...
When I read it back in however, it only retains 6 digits of accuracy.
Any ideas as to what might be causing this?

Thanks!

Matt

[Victor Bazarov]

Matt Jackson wrote:

I've developed a templated binary read/write routine:

template<class T>
void write(ofstream& out,T data){
out.write((char*)&data,sizeof(T));
}

template<class T>
void read(ifstream& in,T& data){
in.read((char*)(&data),sizeof(T));
}
Which I call in a function like:

ofstream out;
out.open("restart.solv",ios::out|ios::binary);
write(out,var);
out.close();

ifstream in;
in.open("restart.solv",ios::in|ios::binary);
read(in,var);

Where var is a double...
When I read it back in however, it only retains 6 digits of accuracy.

How do you know that?

Any ideas as to what might be causing this?

I think the cause is in the part of the program you *didn't* post.

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask

[Jacek Dziedzic]

Matt Jackson wrote:

Where var is a double...
When I read it back in however, it only retains 6 digits of accuracy.
Any ideas as to what might be causing this?

I'd bet on "perhaps it is read in correctly, yet rounded to
6 digits during output only?", but this is a wild guess since
you didn't post code that would demonstrate the problem.

HTH anyway,
- J.