13.2 unsafe.Pointer

Most pointer types are written *T, meaning “a pointer to a variable of type T.” The unsafe.Pointer type is a special kind of pointer that can hold the address of any variable. Of course, we can’t indirect through an unsafe.Pointer using *p because we don’t know what type that expression should have. Like ordinary pointers, unsafe.Pointers are comparable and may be compared with nil, which is the zero value of the type.

An ordinary *T pointer may be converted to an unsafe.Pointer, and an unsafe.Pointer may be converted back to an ordinary pointer, not necessarily of the same type *T. By converting a *float64 pointer to a *uint64, for instance, we can inspect the bit pattern of a floating-point variable:

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