file.read( (TCHAR*)&name_l ength, sizeof(unsigned int) );

[r.z.]

This piece of code crashes my app:
basic_ifstream< TCHARfile(level filepath, ios_base::binar y);
unsigned int name_length;
file.read( (TCHAR*)&name_l ength, sizeof(unsigned int) ); //crashes here -
file is open and contains binary data

It may take me hours to find out why this is incorrect, so if you know it,
please tell me.

[r.z.]

of course TCHAR == wchar_t

[red floyd]

r.z. wrote:

This piece of code crashes my app:
basic_ifstream< TCHARfile(level filepath, ios_base::binar y);
unsigned int name_length;
file.read( (TCHAR*)&name_l ength, sizeof(unsigned int) ); //crashes here -
file is open and contains binary data

It may take me hours to find out why this is incorrect, so if you know it,
please tell me.

You have an error on line 42 of your code.

http://www.parashift.com/c++-faq-lit...t.html#faq-5.8

[r.z.]

Why? This is runtime error and I indicated the exact place where my app
crashes. Nothing more is necessary to tell whether this code is safe or not.

You have an error on line 42 of your code.

http://www.parashift.com/c++-faq-lit...t.html#faq-5.8

[Michael]

r.z. wrote:

This piece of code crashes my app:
basic_ifstream< TCHARfile(level filepath, ios_base::binar y);
unsigned int name_length;
file.read( (TCHAR*)&name_l ength, sizeof(unsigned int) ); //crashes here -
file is open and contains binary data

It may take me hours to find out why this is incorrect, so if you know it,
please tell me.

Add the following code. It should help you debug the problem:

#include <assert.h>

assert(sizeof(u nsigned int) == 4);
assert(sizeof(T CHAR) == 2);
unsigned int num_bytes_read = sizeof(unsigned int) * sizeof(TCHAR);
assert(num_byte s_read == 8);

unsigned int space_available _for_reading_in to = sizeof(name_len gth);
assert(space_av ailable_for_rea ding_into == 4);

assert(4 < 8);

If you're really reading a binary file, you probably shouldn't be using
TCHAR. In other words, if I recompile your code with Unicode
enabled/disabled, your code will have different behavior.

Michael

[David Harmon]

On Thu, 28 Dec 2006 21:23:47 +0100 in comp.lang.c++, "r.z."
<gk***@hjkjhk.p lwrote,

>of course TCHAR == wchar_t

Well, there is your problem. Change TCHAR to (unsigned char).
You are reading (sizeof TCHAR)*(sizeof int) bytes into a variable
that is only (sizeof int).

By the way, "TCHAR" is probably a bad choice of a name, since you will
find Microsoft using it all over much of their code. Even though you
may have nothing to do with Windows systems, you are likely to run into
a conflict sooner or later -- this problem may be it! Just as you would
never start a class name with "C" as they have de-facto reserved that
letter for Microsoft classes.

[David Harmon]

On 28 Dec 2006 13:37:40 -0800 in comp.lang.c++, "Michael"
<mc******@aol.c omwrote,

>assert(4 < 8);

Should be:
assert(4 == 8);