Size constraints in C++

[husker14]

Hi,
I am doing a program with data compression and was wondering if there are any sort of limits on vectors that I did not know about. The program works perfectly as long it is under about 2100 characters, however, if I try to compress anything longer it encodes it, but when I decode it it gives me really random symbols 箸ق㧰ف獲潩㵮ㄢ〮•湥潣楤杮∽楗摮 like these along with a lot of extra boxes. I thought it was a character array at first, but I switched all of them to vectors and it still does this.

Thanks for any help,
husker14

[weaknessforcats]

A vector containing what type?

vector<T>::max_size() will give you the number of elements you can have in the vector. This says nothing about the size of the elements.

I have personally used a vector of a million doubles with no problem.

But this:

program works perfectly as long it is under about 2100 characters

doesn't say what it is.

Those odd characters look like a display of non-ASCII values which makes me think you have some memory corruption operating.

[husker14]

It is a vector of chars, if that helps.

[weaknessforcats]

unless there is a way to convert wchar_t to char?

A vector is an array. The C++ spec specifically says vector must implement a C array. Therefore, if your code works with a char array it will work as a vector.

Now you mention encoding/decoding and you mention a vector of char. I assume you meant a vector of unsigned char. Right?

[JosAH]

A vector is an array. The C++ spec specifically says vector must implement a C array. Therefore, if your code works with a char array it will work as a vector.

Now you mention encoding/decoding and you mention a vector of char. I assume you meant a vector of unsigned char. Right?

The (Chinese?) characers I saw in the OP's example have unicode values far
beyond the range [0,255]. My guess is that the vectors are at least vectors of
unsigned shorts or some utf/8 decoding must be trying to decode those values.
Without seeing any code all I can conclude is that there's definitely something
rotten in the state of Denmark ;-)

kind regards,

Jos

[AdrianH]

Given all the info so far, I'd say it is a problem with your compression algorithm. It is very doubful that it is related to the STL vector class. It should be able to hold (at least) 2.1GiB as long as your OS and computer requirements supports it.

2100 is about 11 bits so I don't see why around that number would cause a problem.


Adrian

[husker14]

I figured out what was going wrong. The problem was an integer was getting too big and so it was turning it into a negative number and screwing everything up.
Thanks for all of your help.

[AdrianH]

I figured out what was going wrong. The problem was an integer was getting too big and so it was turning it into a negative number and screwing everything up.
Thanks for all of your help.

No prob.


Adrian