C++ equivalent?

the istream::read() and ostream::write() functions are probably what you need. They each have versions that operate on a character array, so you can just cast your struct pointer to a char pointer and go wild.

EDIT: whoops. Yeah.

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"Sneftel is correct, if rather vulgar." --Flarelocke

[edited by - sneftel on February 3, 2004 5:06:34 PM]

std::istream::read
std::ostream::write

Technically fread() and fwrite() are part of the C++ standard library too.

However, I'm guessing that get() and put() are *not* what you're looking for. The two paramter version of get() has an implicit \n delimeter. And ostream::put() only writes one character at a time.

edit: @!$% smily code

[edited by - SiCrane on February 3, 2004 5:05:10 PM]

quote:

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Original post by Sneftel
EDIT: whoops. Yeah.

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Sure just edit my post into a non sequitur

AP: If you know how to use fwrite() to output a struct, you should have no trouble using basic_ostream::write().

quote:

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Original post by Anonymous Poster
http://www.cplusplus.com/ref/iostream/ostream/write.html
This definition allows a string and a byte size.

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A char * is a pointer, not a string. When a buffer of memory''s initial address offset is cast to char *, sequential access is byte-wise (because the size of a char is typically a byte). So cast the address of your struct to char * and pass it to write.

Learn your pointers.

Err you're using memory you haven't allocated. Try:

#include <iostream>
#include <fstream>
using namespace std;
typedef struct {
	int i;
	char *p;
	float d;
} ff;
int main() {
	ofstream out("a.txt", (ios::out | ios::binary));
	ifstream in("a.txt", (ios::in | ios::binary));
	ff *test = new ff(); // allocate memory
	test->i = 500;
	test->p = "test";
	test->d = 2.00432f;
	char *t = (char *) test;
	out.write(t, sizeof(ff));
	out.close();
	in.read(t, sizeof(ff));
	// no need to assign back to test beacuse t == test
	cout << test->i << endl;
	in.close();
	delete test; // delete memory
	return 0;
}   

EDIT2: oh, and as this is c++ you don't need to typedef your struct:

struct ff{
	int i;
	char *p;
	float d;
}; 

will do.

Enigma

EDIT: missed a line break

[edited by - Enigma on February 3, 2004 6:22:50 PM]

[edited by - Enigma on February 3, 2004 6:24:20 PM]

Just in case you''re interested, you can handle

struct

s like a normal data type. So instead of saying

typedef struct {
  int   i;
  char* p;
  float d;
} ff;

You could just go and say:

struct ff {
  int   i;
  char* p;
  float d;
};

I just thought you might want to know!

cya,
Drag0n

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