When I run a program using the read part of fstream, I get this return value:

-1073741819

the actual function is part of a corrupt for loop, which I will try to explain:

for(int i = 0; i < vrs_top_i * 3; i += 3)
{
        int X1x = FileRead(file2, i + 1);
        int X1y = FileRead(file2, i + 2);
        char X1sym = FileRead(file2, i + 3);
        viral_data.add(new X1(X1x, X1y, X1sym));
}

vrs_top_i is a variable declared like this: int vrs_top_i = FileRead(file2, 0);

add is a function for a custom list I made, essentially the same as push_back() for vectors. X1 is a class I made with a constructor that takes three arguments, two ints and a char.

Now for the corrupt part of the loop:

now, when I put "exit(0);" under the third line of the loop "char X1sym...+ 3);" (or anywhere else in the loop, for that matter) It does what you expect: ends the program with a return value of zero.

but when I put "if(i == 0)exit(0);", or "if(i == 3)", I get the aforementioned return value.

So I'm guessing that means that i is never 0 or 3.

So does anybody know what the return value means?

NB: FileRead is declared like so:

int FileRead(std::fstream& file, int pos)
{
int data;
file.seekg(file.beg + pos * sizeof(int));
file.read(reinterpret_cast<char*>(&data), sizeof(data));
return data;
}

-1073741819 is the decimal representation of 0xC0000005. This is not actually a return value--it's a Windows code for STATUS_ACCESS_VIOLATION, which is what happens when your program accesses invalid memory.

Effectively, your program has a bug and is accessing invalid memory and crashes. The code that you're seeing is Windows' way of telling you so.

Convert it to hex and you'll get 0xc0000005. An error code you should get to know well. It's a general protection fault, or dereferencing a garbage pointer in other words.

At least one the reason your code doesn' work as intended:

Your FileRead reads i-th int from a file. But you are using it to read a char, which breaks the math of calculating your addresses. Your record length is not 3 * sizeof(int), but 2 * sizeof(int) + sizeof(char).

In other words, your seekg will be set to an incorrect position after the reading of a char.