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What is non const reference?
I understand now that a const reference to a non const object does have a purpose: to prevent the reference from modifying the object. The non const object can still be modified by other means but not by this const reference.
Can a pointer be passed by reference?
6 Answers. You would want to pass a pointer by reference if you have a need to modify the pointer rather than the object that the pointer is pointing to. This is similar to why double pointers are used; using a reference to a pointer is slightly safer than using pointers.
Can non const pointers be changed?
A pointer to a non-const value can change the value it is pointing to. These can not point to a const value. A pointer to a const value treats the value as const (even if it is not), and thus can not change the value it is pointing to.
What is const member function?
The const member functions are the functions which are declared as constant in the program. The object called by these functions cannot be modified. It is recommended to use const keyword so that accidental changes to object are avoided. A const member function can be called by any type of object.
How does a const reference work?
if you are using const reference, you pass it by reference and the original data is not copied. in both cases, the original data cannot be modified from inside the function. EDIT: In certain cases, the original data might be able to get modified as pointed out by Charles Bailey in his answer.
When is it better to pass by const pointer or reference?
For example when you are passing a class with some properties to a function it’s better to pass it by const reference, In other hand if your are passing types like int or just a pointer it’s better not to use references because then you loos performance due to de-reference process.
Is it bad to store a reference as a pointer?
I’d say yes it is standard to have a reference that is taken as a pointer (as in I have seen it in multiple projects) and yes it is bad as it does hide the problem of object lifetime. And the const cast is unnecessary and completely horrible. At the very least it should be a ref that is passed in, not a const ref.
When to use const and const reference in function args?
In general, for an argument passing data into a function, you pass small items (such as an int) by value, and potentially larger items by reference to const. In the machine code the reference to const may be optimized away or it may be implemented as a pointer.
How to pass a unique _ ptr argument to a constructor or function?
That’s all it does. Because Base::Base (std::unique_ptr n) takes its argument by value rather than by r-value reference, C++ will automatically construct a temporary for us. It creates a std::unique_ptr from the Base&& that we gave the function via std::move (nextBase).