static cast

In C++ type conversion, the static_cast operator does an explicit type conversion.^[1]

Syntax

static_cast<type> (object);

The type parameter must be a data type for which there is a known method for converting object to, whether this be a builtin or through a casting function. It can be a reference or an enumerator. All types of conversions that are well-defined and allowed by the compiler are done using static_cast.^[2]

The static_cast operator can be used for operations such as

• Converting a pointer of a base class to a pointer of a derived class,
• Convert numeric data types such as enums to ints or ints to floats.

However, static_cast conversions are not necessarily safe as no run-time type check is done which can cause casting between incompatible data types, for example pointers. However, this is checked at compile time to prevent casting obvious incompatibles. Also, static_cast between pointer of a virtual base to pointer of derived is not allowed, because of the object layout model.

See also

• dynamic cast
• reinterpret_cast
• const_cast

References

1. Programming: Principles and Practice Using C++. United States of America: Addison-Wesley. 2008. p. 594. ISBN 0321543726.
2. Thinking in C++. United States of America: Alan Apt. 2000. p. 857. ISBN 0-13-979809-9.