MAINT: Remove subclass paths from scalar_value

If a user-dtype uses a subclass of an existing NumPy scalar
(which is probably rare or non-existing), it cannot be flexible
or object.
Thus the alignment logic should always work (as it should work
for our scalars as well), and it is unlikely that testing for
subclasses is not just a waste of time.

1 files changed, 4 insertions, 77 deletions

diff --git a/numpy/core/src/multiarray/scalarapi.c b/numpy/core/src/multiarray/scalarapi.c
index 0e93cbbe9..6d1ffe002 100644
--- a/numpy/core/src/multiarray/scalarapi.c
+++ b/numpy/core/src/multiarray/scalarapi.c
@@ -87,83 +87,12 @@ scalar_value(PyObject *scalar, PyArray_Descr *descr)
     }
 
     /*
-     * Must be a user-defined type --- check to see which
-     * scalar it inherits from.
+     * Must be a user defined type with an associated (registered) dtype.
+     * Thus, it cannot be flexible (user dtypes cannot be), so we can (and
+     * pretty much have no choice but to) assume the below logic always works.
+     * I.e. this assumes that the logic would also works for most of our types.
      */
 
-#define _CHK(cls) PyObject_IsInstance(scalar, \
-            (PyObject *)&Py##cls##ArrType_Type)
-#define _IFCASE(cls) if (_CHK(cls)) return &PyArrayScalar_VAL(scalar, cls)
-
-    if (_CHK(Number)) {
-        if (_CHK(Integer)) {
-            if (_CHK(SignedInteger)) {
-                _IFCASE(Byte);
-                _IFCASE(Short);
-                _IFCASE(Int);
-                _IFCASE(Long);
-                _IFCASE(LongLong);
-                _IFCASE(Timedelta);
-            }
-            else {
-                /* Unsigned Integer */
-                _IFCASE(UByte);
-                _IFCASE(UShort);
-                _IFCASE(UInt);
-                _IFCASE(ULong);
-                _IFCASE(ULongLong);
-            }
-        }
-        else {
-            /* Inexact */
-            if (_CHK(Floating)) {
-                _IFCASE(Half);
-                _IFCASE(Float);
-                _IFCASE(Double);
-                _IFCASE(LongDouble);
-            }
-            else {
-                /*ComplexFloating */
-                _IFCASE(CFloat);
-                _IFCASE(CDouble);
-                _IFCASE(CLongDouble);
-            }
-        }
-    }
-    else if (_CHK(Bool)) {
-        return &PyArrayScalar_VAL(scalar, Bool);
-    }
-    else if (_CHK(Datetime)) {
-        return &PyArrayScalar_VAL(scalar, Datetime);
-    }
-    else if (_CHK(Flexible)) {
-        if (_CHK(String)) {
-            return (void *)PyBytes_AS_STRING(scalar);
-        }
-        if (_CHK(Unicode)) {
-            /* Treat this the same as the NPY_UNICODE base class */
-
-            /* lazy initialization, to reduce the memory used by string scalars */
-            if (PyArrayScalar_VAL(scalar, Unicode) == NULL) {
-                Py_UCS4 *raw_data = PyUnicode_AsUCS4Copy(scalar);
-                if (raw_data == NULL) {
-                    return NULL;
-                }
-                PyArrayScalar_VAL(scalar, Unicode) = raw_data;
-                return (void *)raw_data;
-            }
-            return PyArrayScalar_VAL(scalar, Unicode);
-        }
-        if (_CHK(Void)) {
-            /* Note: no & needed here, so can't use _IFCASE */
-            return PyArrayScalar_VAL(scalar, Void);
-        }
-    }
-    else {
-        _IFCASE(Object);
-    }
-
-
     /*
      * Use the alignment flag to figure out where the data begins
      * after a PyObject_HEAD
@@ -176,8 +105,6 @@ scalar_value(PyObject *scalar, PyArray_Descr *descr)
         memloc = ((memloc + align - 1)/align)*align;
     }
     return (void *)memloc;
-#undef _IFCASE
-#undef _CHK
 }
 
 /*NUMPY_API