PyHash API
**********

See also the "PyTypeObject.tp_hash" member and Hashing of numeric
types.

type Py_hash_t

   Hash value type: signed integer.

   Added in version 3.2.

type Py_uhash_t

   Hash value type: unsigned integer.

   Added in version 3.2.

PyHASH_MODULUS

   The Mersenne prime "P = 2**n -1", used for numeric hash scheme.

   Added in version 3.13.

PyHASH_BITS

   The exponent "n" of "P" in "PyHASH_MODULUS".

   Added in version 3.13.

PyHASH_MULTIPLIER

   Prime multiplier used in string and various other hashes.

   Added in version 3.13.

PyHASH_INF

   The hash value returned for a positive infinity.

   Added in version 3.13.

PyHASH_IMAG

   The multiplier used for the imaginary part of a complex number.

   Added in version 3.13.

type PyHash_FuncDef

   Hash function definition used by "PyHash_GetFuncDef()".

   Py_hash_t (*const hash)(const void*, Py_ssize_t)

      Hash function.

   const char *name

      Hash function name (UTF-8 encoded string).

   const int hash_bits

      Internal size of the hash value in bits.

   const int seed_bits

      Size of seed input in bits.

   Added in version 3.4.

PyHash_FuncDef *PyHash_GetFuncDef(void)

   Get the hash function definition.

   See also: **PEP 456** “Secure and interchangeable hash algorithm”.

   Added in version 3.4.

Py_hash_t Py_HashPointer(const void *ptr)

   Hash a pointer value: process the pointer value as an integer (cast
   it to "uintptr_t" internally). The pointer is not dereferenced.

   The function cannot fail: it cannot return "-1".

   Added in version 3.13.

Py_hash_t Py_HashBuffer(const void *ptr, Py_ssize_t len)

   Compute and return the hash value of a buffer of *len* bytes
   starting at address *ptr*. The hash is guaranteed to match that of
   "bytes", "memoryview", and other built-in objects that implement
   the buffer protocol.

   Use this function to implement hashing for immutable objects whose
   "tp_richcompare" function compares to another object’s buffer.

   *len* must be greater than or equal to "0".

   This function always succeeds.

   Added in version 3.14.

Py_hash_t PyObject_GenericHash(PyObject *obj)

   Generic hashing function that is meant to be put into a type
   object’s "tp_hash" slot. Its result only depends on the object’s
   identity.

   **CPython implementation detail:** In CPython, it is equivalent to
   "Py_HashPointer()".

   Added in version 3.13.
