digitalmars.D.learn - How to replace the keyword "nan" to check the contract assert?

```Hi,
How do I replace double.init?

import std.stdio : writeln;
import std.algorithm : uninitializedFill;

void main() {

double[] arr = new double;
uninitializedFill(arr[0 .. \$ - 2], 3.25);
writeln(arr);
assert(arr == [3.25, 3.25, 3.25, 3.25, double.init,
double.init]); /* not work */
}
```
Mar 20 2015
```On 03/20/2015 09:24 PM, Dennis Ritchie wrote:> Hi,
How do I replace double.init?

import std.stdio : writeln;
import std.algorithm : uninitializedFill;

void main() {

double[] arr = new double;
uninitializedFill(arr[0 .. \$ - 2], 3.25);
writeln(arr);
assert(arr == [3.25, 3.25, 3.25, 3.25, double.init, double.init]);
/* not work */
}

nan cannot be used in comparisons. It is neither greater than nor less
than any value. You cannot even compare it against itself. nan==nan
would always be false.

The solution is to call std.math.isNaN. In this case, you have to split
the assert into two. You can achieve the same thing in may ways but the
following works:

assert(arr[0 .. \$ - 2] == [3.25, 3.25, 3.25, 3.25]);

import std.algorithm;
import std.math;
assert(arr[\$ - 2 .. \$].all!isNaN);

Ali
```
Mar 20 2015
```On Saturday, 21 March 2015 at 04:53:20 UTC, Ali Çehreli wrote:
nan cannot be used in comparisons. It is neither greater than
nor less than any value. You cannot even compare it against
itself. nan==nan would always be false.

The solution is to call std.math.isNaN. In this case, you have
to split the assert into two. You can achieve the same thing in
may ways but the following works:

assert(arr[0 .. \$ - 2] == [3.25, 3.25, 3.25, 3.25]);

import std.algorithm;
import std.math;
assert(arr[\$ - 2 .. \$].all!isNaN);

Thanks.
```
Mar 20 2015