Function bool_select 

pub fn bool_select<R, T, B, D, I>(
    tensor: &TensorAny<R, T, B, D>,
    axis: isize,
    mask: I,
) -> Tensor<T, B, D>
where
    R: DataAPI<Data = <B as DeviceRawAPI<T>>::Raw>,
    D: DimAPI + DimSmallerOneAPI,
    D::SmallerOne: DimAPI,
    B: DeviceAPI<T> + DeviceIndexSelectAPI<T, D> + DeviceCreationAnyAPI<T>,
    I: TryInto<AxesIndex<bool>, Error = Error>,

Returns a new tensor, which indexes the input tensor along dimension axis using the boolean entries in mask.