reinterpret_cast
Basically, reinterpret_cast
reinterprets the bit pattern at a specific location as a different type.
See for example here: http://publib.boulder.ibm.com/infocenter/lnxpcomp/v7v91/index.jsp?topic=%2Fcom.ibm.vacpp7l.doc%2Flanguage%2Fref%2Fclrc05keyword_reinterpret_cast.htm
The reinterpret_cast operator produces a value of a new type that has the same bit pattern as its argument.
A static cast
converts the argument instead of just reinterpreting it. You can try this out by static_casting an int
to float
and reinterpret_casting an int
to float
. The result will be totally different.
There's nothing fancy here. it's really just intended to reinterpret something.
From standard 5.3.10, reinterpret_cast is aimed to cater the following cases:
- A pointer can be explicitly converted to any integral type large enough to hold it.
- A value of integral type or enumeration type can be explicitly converted to a pointer.
- A pointer to a function can be explicitly converted to a pointer to a function of a different type.
- A pointer to an object can be explicitly converted to a pointer to a different object type.
- Converting a pointer to a function into a pointer to an object type or vice versa is conditionally-supported.
- The null pointer value (4.10) is converted to the null pointer value of the destination type.
- A prvalue of type “pointer to member of X of type T1” can be explicitly converted to a prvalue of a different type “pointer to member of Y of type T2” if T1 and T2 are both function types or both object types.
- An lvalue expression of type T1 can be cast to the type “reference to T2” if an expression of type “pointer to T1” can be explicitly converted to the type “pointer to T2” using a reinterpret_cast. That is, a reference cast reinterpret_cast < T& >(x) has the same effect as the conversion *reinterpret_cast< T* >(&x) with the built-in & and * operators (and similarly for reinterpret_cast< T&& >(x)).