Issue with using std::copy

I am getting warning when using the std copy function.

I have a byte array that I declare.

byte *tstArray = new byte[length];

Then I have a couple other byte arrays that are declared and initialized with some hex values that i would like to use depending on some initial user input.

I have a series of if statements that I use to basically parse out the original input, and based on some string, I choose which byte array to use and in doing so copy the results to the original tstArray.

For example:

if(substr1 == "15")
{
   std::cout<<"Using byte array rated 15"<<std::endl;
   std::copy(ratedArray15,ratedArray15+length,tstArray);
} 

The warning i get is
warning C4996: ‘std::copy’: Function call with parameters
that may be unsafe
– this call relies on the caller to check that the passed
values are correct.

A possible solution is to to disable this warning is by useing -D_SCL_SECURE_NO_WARNINGS, I think. Well, that is what I am researching.

But, I am not sure if this means that my code is really unsafe and I actually needed to do some checking?

Issue with using std::copy