在c++中，当我大量使用多级指针时，使用typedef来简化是不是一个好办法？

Question

In c++, when I am using multi-level pointer a lot, is it a good way to use typedef to simplify it?

Answer 1

Yes, It can be a good practice to increase code readability.

Lets state you have:

class Foo
{
  public:
    Foo(const myotherlib::x509::certificate& cert);

  private:

    myotherlib::x509::certificate m_cert;
}

It is a good idea to typedef things a little bit:

class Foo
{
  public:

    typedef myotherlib::x509::certificate cert_type;

    Foo(const cert_type& cert);

  private:

    cert_type m_cert;
}

This increases the code readability and has the neat side effect that if you ever change the underlying certificate class, you just have to change the typedef .

And to answer more completely, the same rule might apply to "multi-level" pointers: if you really are writting Foo*** all over the place it can indeed be a good idea to make things more readable, and typedef is a good tool for that.

If one day you decide to replace your Foo*** with a class that has the same semantics, the change will be trivial, not only in your code, but in any client code that uses yours as well.

Answer 2

Yes, it's always an good idea to have it typedef. For example,

typedef int* intp;
typedef int** intpp;

Now, if your code is really organized, then you can change simply typedef to use your custom or any other smart pointer. eg

typedef auto_ptr<int> intp;

This can be a good way for debugging.