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: activation.rs
    path of file: ./repos/burn/crates/burn-tensor/src/tensor/ops
    
    the code of the file until where you have to start completion: use crate::tensor::ops::tensor::FloatTensorOps;
use crate::{backend::Backend, ElementConversion};
use core::f64::consts::SQRT_2;

use super::FloatTensor;

/// Activation function operations.
///
/// This trait let backend implementations override activation functions for better performance.
pub trait ActivationOps<B: Backend> {
    /// Applies the ReLU activation function.
    ///
    /// # Arguments
    ///
    /// * `tensor` - The tensor.
    ///
    /// # Returns
    
    
    fn sigmoid<const D: usize>(tensor: FloatTensor<B, D>) -> FloatTensor<B, D> {
        let tensor_full = B::float_to_full_precision(&tensor);
        let tensor_tmp = B::FullPrecisionBackend::float_exp(B::FullPrecisionBackend::float_neg(
            B::FullPrecisionBackend::float_log(B::FullPrecisionBackend::float_add_scalar(
                B::FullPrecisionBackend::float_exp(B::FullPrecisionBackend::float_neg(tensor_full)),
                1.0.elem(),
            )),
        ));

        B::float_from_full_precision(tensor_tmp)
    }