In which cases is it recommended to use static_cast in C++?

static_cast in C++ is recommended for:

• Converting between compatible types, for example, from int to double or vice versa.
• Casting pointers or references in a class hierarchy upwards (upcasting), when it is safe and explicit.
• Converting void* to a pointer to a specific type.

static_cast does not perform runtime checks, so it should be used when you are confident in the correctness of the conversion.

Example:

class Base {};
class Derived : public Base {};

Derived d;
Base* b = static_cast<Base*>(&d); // safe upcast

int i = 10;
double dval = static_cast<double>(i); // int -> double