ENH: core: Change the ones_like ufunc so it doesn't do type checking

Since ones_like is a ufunc (unlike zeros_like and empty_like), it by
default checks the casting rule. This disables that check completely.

3 files changed, 31 insertions, 1 deletions

diff --git a/numpy/core/code_generators/generate_umath.py b/numpy/core/code_generators/generate_umath.py
index 957607f40..296f4683d 100644
--- a/numpy/core/code_generators/generate_umath.py
+++ b/numpy/core/code_generators/generate_umath.py
@@ -333,7 +333,7 @@ defdict = {
 'ones_like' :
     Ufunc(1, 1, None,
           docstrings.get('numpy.core.umath.ones_like'),
-          'PyUFunc_SimpleUnaryOperationTypeResolution',
+          'PyUFunc_OnesLikeTypeResolution',
           TD(noobj),
           TD(O, f='Py_get_one'),
           ),
diff --git a/numpy/core/src/umath/ufunc_object.c b/numpy/core/src/umath/ufunc_object.c
index b26221e23..69f9afecf 100644
--- a/numpy/core/src/umath/ufunc_object.c
+++ b/numpy/core/src/umath/ufunc_object.c
@@ -2012,6 +2012,27 @@ PyUFunc_SimpleUnaryOperationTypeResolution(PyUFuncObject *ufunc,
 }
 
 /*
+ * The ones_like function shouldn't really be a ufunc, but while it
+ * still is, this provides type resolution that always forces UNSAFE
+ * casting.
+ */
+NPY_NO_EXPORT int
+PyUFunc_OnesLikeTypeResolution(PyUFuncObject *ufunc,
+                                NPY_CASTING NPY_UNUSED(casting),
+                                PyArrayObject **operands,
+                                PyObject *type_tup,
+                                PyArray_Descr **out_dtypes,
+                                PyUFuncGenericFunction *out_innerloop,
+                                void **out_innerloopdata)
+{
+    return PyUFunc_SimpleUnaryOperationTypeResolution(ufunc,
+                        NPY_UNSAFE_CASTING,
+                        operands, type_tup, out_dtypes,
+                        out_innerloop, out_innerloopdata);
+}
+
+
+/*
  * This function applies special type resolution rules for the case
  * where all the functions have the pattern XX->X, using
  * PyArray_ResultType instead of a linear search to get the best
diff --git a/numpy/core/src/umath/ufunc_object.h b/numpy/core/src/umath/ufunc_object.h
index 2a5fd63a1..59754380c 100644
--- a/numpy/core/src/umath/ufunc_object.h
+++ b/numpy/core/src/umath/ufunc_object.h
@@ -26,6 +26,15 @@ PyUFunc_SimpleUnaryOperationTypeResolution(PyUFuncObject *ufunc,
                                 void **out_innerloopdata);
 
 NPY_NO_EXPORT int
+PyUFunc_OnesLikeTypeResolution(PyUFuncObject *ufunc,
+                                NPY_CASTING casting,
+                                PyArrayObject **operands,
+                                PyObject *type_tup,
+                                PyArray_Descr **out_dtypes,
+                                PyUFuncGenericFunction *out_innerloop,
+                                void **out_innerloopdata);
+
+NPY_NO_EXPORT int
 PyUFunc_SimpleBinaryOperationTypeResolution(PyUFuncObject *ufunc,
                                 NPY_CASTING casting,
                                 PyArrayObject **operands,