.&(_:_:)

A vector mask that is the pointwise logical conjunction of the inputs.

static func .& (a: SIMDMask<Storage>, b: SIMDMask<Storage>) -> SIMDMask<Storage>

Equivalent to:

var result = SIMDMask<SIMD64<Int32>>()
for i in result.indices {
  result[i] = a[i] && b[i]
}

Note that unlike the scalar && operator, the SIMD .& operator always fully evaluates both arguments.