Can't use float array in map

[Andrej Mitrovic]

test case:

import std.algorithm;

void main()
{
    float[10] arr;
    arr[] = 0.0;
    map!((ref float sample){ sample = 1.0; })(arr[]);
}

D:\DMD\dmd2\windows\bin\..\..\src\phobos\std\algorithm.d(382): Error: nan is 
not an lvalue

This looks like a bug to me?