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: lexical.rs
    path of file: ./repos/databend/src/common/arrow/src/arrow/util
    
    the code of the file until where you have to start completion: // Copyright 2020-2022 Jorge C. Leit√£o
// Copyright 2021 Datafuse Labs
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

/// Converts numeric type to a `String`
#[inline]
pub fn lexical_to_bytes<N: lexical_core::ToLexical>(n: N) -> Vec<u8> {
    let mut buf = Vec::<u8>::with_capacity(N::FORMATTED_SIZE_DEC
    
pub fn lexical_to_bytes_mut<N: lexical_core::ToLexical>(n: N, buf: &mut Vec<u8>) {
    buf.clear();
    buf.reserve(N::FORMATTED_SIZE_DECIMAL);
    unsafe {
        // JUSTIFICATION
        //  Benefit
        //      Allows using the faster serializer lexical core and convert to string
        //  Soundness
        //      Length of buf is set as written length afterwards. lexical_core
        //      creates a valid string, so doesn't need to be checked.
        let slice = std::slice::from_raw_parts_mut(buf.as_mut_ptr(), buf.capacity());

        //  Safety:
        //  Omits an unneeded bound check as we just ensured that we reserved `N::FORMATTED_SIZE_DECIMAL`
        #[cfg(debug_assertions)]
        {
            let len = lexical_core::write(n, slice).len();
            buf.set_len(len);
        }
        #[cfg(not(debug_assertions))]
        {
            let len = lexical_core::write_unchecked(n, slice).len();
            buf.set_len(len);
        }
    }
}