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My compiler is the latest VC++ 2013 RC.
void f() { int n1 = 0; int n2 = reinterpret_cast<int>(n1); // error C2440 } error C2440: 'reinterpret_cast' : cannot convert from 'int' to 'int'
Why can reinterpret_cast not be used in such an obvious case?
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reinterpret_cast is a type of casting operator used in C++. It is used to convert a pointer of some data type into a pointer of another data type, even if the data types before and after conversion are different. It does not check if the pointer type and data pointed by the pointer is same or not.
The reinterpret_cast allows the pointer to be treated as an integral type. The result is then bit-shifted and XORed with itself to produce a unique index (unique to a high degree of probability). The index is then truncated by a standard C-style cast to the return type of the function.
static_cast only allows conversions like int to float or base class pointer to derived class pointer. reinterpret_cast allows anything, that's usually a dangerous thing and normally reinterpret_cast is rarely used, tipically to convert pointers to/from integers or to allow some kind of low level memory manipulation.
No. It is a purely compile-time construct. It is very dangerous, because it lets you get away with very wrong conversions.
According to cppreference.com the following conversion is available only since C++11:
An expression of integral, enumeration, pointer, or pointer-to-member type can be converted to its own type. The resulting value is the same as the value of expression.
which may not be implemented in Visual Studio 2013 RC yet.
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