Shylock Hg

My own blog powered by Hugo and Ivy.

Reference And Dereference In Programming Language

2019-01-14


Naive Stage

The naive reference is the pointer in c programming language.In c language, we use & and * operator to reference and dereference one data structure, such as bellow:

data_t *p = &data;  //!< reference `data`
*p;  //!< dereference `data`

Primitive reference type

The modern programming language not recommend pointer but independent reference type.In c++ language, we use & operator to reference data structure and automatic dereference the reference by compiler, such as bellow:

data_t &r = data;  //!< reference `data`
r;  //!< automatic dereference `data`

The difference of Pointer, Reference

Difference Pointer Reference
Automatic dereference N Y
Immutable N Y

The Ownership and Borrowing

The Ownership and Borrowing is the concepts in RUST programming language.But they are related to reference for that reference is one implementation of Borrowing.
The main difference of Ownership and Borrowing is the Drop trait, Owner implement it but Borrower not.There are some same concepts in other languages, such as Smart Pointer(One implementations of Ownership) and reference(One implementation of Borrowing) in c++, through they distinguish Ownership by destructor.
There are some typical implementations of Ownership and Borrowing in RUST as bellow:

Owner Borrower
Box, Rc and String etc. reference, slice and Iter etc.