const overloading in C++

In C++, a function's signature depends partly on whether or not it's const. This means that a class can have two member functions with identical signatures except that one is const and the other is not. If you have a class like this, then the compiler will
decide which function to call based on the object you call it on: if it's a const instance of the class, the const version of the function will be called; if the object isn't const, the other version will be called.

In what circumstances might you want to take advantage of this feature?

 

http://stackoverflow.com/questions/251159/what-is-the-use-of-const-overloading-in-c