version(D_SIMD)
{
    static assert(!is(         float       == __vector)); 
    static assert(!is(         float[1]    == __vector)); 
    static assert(!is(         float[4]    == __vector)); 
    static assert( is(__vector(float[4])   == __vector)); 
    static assert(!is(__vector(float[3])   == __vector)); 
    static assert(!is(__vector(float[5])   == __vector)); 
    static assert( is(__vector(float[4]) X == __vector) &&
                   is(X == float[4])); 
    static assert( is(__vector(byte[16]) X == __vector) &&
                   is(X == byte[16])); 
}