You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: init.rs
    path of file: ./repos/candle/candle-nn/src
    
    the code of the file until where you have to start completion: //! Variable initialization.
// This is based on:
// https://github.com/pytorch/pytorch/blob/07107919297db3f8ab37f11c12666b6d6d5f692e/torch/nn/init.py#
use candle::{DType, Device, Result, Shape, Tensor, Var};

/// Number of features as input or output
    
    pub fn for_shape(&self, shape: &Shape) -> usize {
        let dims = shape.dims();
        let receptive_field_size: usize = dims.iter().skip(2).product();
        match &self {
            FanInOut::FanIn => {
                if dims.len() < 2 {
                    1
                } else {
                    dims[1] * receptive_field_size
                }
            }
            FanInOut::FanOut => {
                if dims.is_empty() {
                    1
                } else {
                    dims[0] * receptive_field_size
                }
            }
        }
    }