Coverpoint for "rand bit [255:0] foo"

Coverage
1

rand bit [255:0] foo;

I wish to write a coverpoint (location_cp) to indicate which of the bits in foo have become 1.

e.g.
If foo [0] = 1, then location_cp should indicate that bit 0 of foo has become 1.
If foo [1] = 1, then location_cp should indicate that bit 1 of foo has become 1.
.
.
.
.
If foo and foo[y] are 1, then location_cp should indicate that bits x and y of foo have become 1, and so on.

How do I do this?
Thank You!

2

See if this post section on covergroup expressions gives you an idea: http://go.mentor.com/ready-for-systemverilog-2012

3

class cov;
bit [255:0] foo_cp;

function new();
foo_cg = new();
endfunction
covergroup foo_cg();
option.name = “foo_cov”;
option.per_instance = 1;

 cov_foo:coverpoint foo_cp {
    bins foo_bin[] = foo_cp with {item %8 == 0};  
  }

endgroup