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: type_map.rs
    path of file: ./repos/c2rust/c2rust-refactor/src
    
    the code of the file until where you have to start completion: //! Helper definitions for constructing a mapping between `ast::Ty`s and some higher-level
//! representation (usually `ty::Ty` or `LabeledTy`).

use std::fmt::Debug;

use rustc::hir;
use rustc::hir::def_id::DefId;
use rustc::ty;
use syntax::ast::*;
use syntax::visit::{self, Visitor};

use crate::context::HirMap;

/// Provider of a higher-level type representation.
///
/// Methods can return `None` under any circumstances to indicate that the provider can't find a
///
    
    fn visit_foreign_item(&mut self, i: &'ast ForeignItem) {
        let def_id = self.hir_map.local_def_id_from_node_id(i.id);
        match i.kind {
            ForeignItemKind::Fn(ref decl, _) => {
                if let Some(sig) = self.source.fn_sig(def_id) {
                    self.record_fn_decl(sig, &decl);
                }
            }

            ForeignItemKind::Static(ref ast_ty, _) => {
                if let Some(ty) = self.source.def_type(def_id) {
                    self.record_ty(ty, ast_ty);
                }
            }
            ForeignItemKind::Ty => {}
            ForeignItemKind::Macro(..) => {}
        }

        visit::walk_foreign_item(self, i);
    }