What are the different ways to use casting in C++?
In C++, there are four types of casting: static_cast, dynamic_cast, const_cast, and reinterpret_cast.
- Static_cast is used to perform regular conversions, such as converting a pointer or reference from one type to another, or converting one arithmetic type to another type. Static_cast performs the conversion at compile time, so it cannot check if the conversion is valid.
- dynamic_cast is mainly used for performing polymorphic type conversions at runtime, it is only applicable to pointers or references of classes with virtual functions. dynamic_cast will check if the conversion is valid, and if it is not, it will return nullptr (for pointers) or throw std::bad_cast exception (for references).
- const_cast: Used to remove the const or volatile properties of a variable. This type of cast can change the const nature of a pointer or reference, but be careful not to break const correctness.
- reinterpret_cast is used for performing low-level conversions, such as converting one pointer type to another pointer type, or converting an integer type to a pointer type. It enforces the conversion, which can potentially lead to undefined behavior, and should be avoided in regular code.
Here are four commonly used casting methods in C++, choose the appropriate type according to the specific situation.