Can you cast pointers in C?
In the C language, casting is a construct to view a data object temporarily as another data type. When you cast pointers, especially for non-data object pointers, consider the following characteristics and constraints: You can cast a pointer to another pointer of the same IBM® i pointer type.
Is Const cast undefined behavior?
Even though const_cast may remove constness or volatility from any pointer or reference, using the resulting pointer or reference to write to an object that was declared const or to access an object that was declared volatile invokes undefined behavior. So yes, modifying constant variables is undefined behavior.
What is pointer type casting in C?
A pointer is an arrow that points to an address in memory, with a label indicating the type of the value. The address indicates where to look and the type indicates what to take. Casting the pointer changes the label on the arrow but not where the arrow points. d in main is a pointer to c which is of type char .
What is undefined Behaviour C?
In computer programming, undefined behavior (UB) is the result of executing a program whose behavior is prescribed to be unpredictable, in the language specification to which the computer code adheres. In the C community, undefined behavior may be humorously referred to as “nasal demons”, after a comp. std.
Why is const_cast bad?
The whole purpose of const is to prevent you from modifying something, that’s why your code generates an error. Adding in const_cast is basically telling the compiler to shut up, that you know what you’re doing. That’s why it’s not a good idea. If you don’t want it to be const , don’t declare it const .
What is undefined value in C?
C has no specific undefined value. A function that wants to return an undefined value might indicate failure. Sometimes -1 is failure, sometimes 0 is failure, sometimes 0 is success; one has to look up the documentation to know exactly which. For a pointer, the undefined value is often pointer 0, the NULL pointer.