What is use of const volatile ?

Question

Let me put this in other way , const qualifier will not allow to change you the value so what is the need of going with const volatile. Do we really need it in our day to day programming

Comments

check this for volatile definition
http://queryhome.com/18863/why-we-need-volatile-variables-in-c

now coming to const volatile
An object marked as const volatile will not be permitted to be changed by the code (an error will be raised due to the const qualifier).

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As per my understanding.. Volatile means value can be changed within a code and const means value should never be changed.
then my question is what is the meaning/use of taking variable as a const volatile?

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const volatile will not be permitted to be changed...
then what is the use of taking volatile and const both together?

Answer 1

For example

const volatile int T=10;

const qualifier means that the T cannot be modified through code. If you attempt to do so the compiler will provide a diagnostic. Volatile still means that compiler cannot optimize or reorder access to T.

Practical Usage:

Accessing shared memory in read-only mode.
Accessing hardware registers in read-only mode.