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: metadata.rs
    path of file: ./repos/windows-rs/crates/libs/bindgen/src
    
    the code of the file until where you have to start completion: use std::collections::*;
pub use windows_metadata::*;

#[derive(Clone)]
pub struct Interface {
    pub ty: Type,
    pub kind: InterfaceKind,
}

#[derive(Copy, Clone, PartialEq, Eq)]
pub enum InterfaceKind {
    None,
    Default,
    Overridable,
    Static,
    Base,
}

#[derive(Copy, Clone, PartialEq, Eq)]
pub struct QueryPosition {
    pub object: usize,
    pub guid: usize,
}

#[derive(Copy, Clone, PartialEq, Eq)]
pub enum SignatureKind {
    Query(QueryPosition),
    QueryOptional(QueryPosition),
    ResultValue,
    ResultVoid,
    ReturnStruct,
    ReturnValue,
    ReturnVoid,
    PreserveSig,
}

#[derive(Copy, Clone, Eq, PartialEq)]
pub enum SignaturePar
    
pub fn type_def_has_explicit_layout(row: TypeDef) -> bool {
    if row.kind() != TypeKind::Struct {
        return false;
    }
    fn check(row: TypeDef) -> bool {
        if row.flags().contains(TypeAttributes::ExplicitLayout) {
            return true;
        }
        if row.fields().any(|field| type_has_explicit_layout(&field.ty(Some(row)))) {
            return true;
        }
        false
    }
    let type_name = row.type_name();
    if type_name.namespace.is_empty() {
        check(row)
    } else {
        for row in row.reader().get_type_def(type_name.namespace, type_name.name) {
            if check(row) {
                return true;
            }
        }
        false
    }
}