1 files changed, 48 insertions, 0 deletions
diff --git a/tests/run/special_methods_T561_py38.pyx b/tests/run/special_methods_T561_py38.pyx
new file mode 100644
index 000000000..9908a2504
--- /dev/null
+++ b/tests/run/special_methods_T561_py38.pyx
@@ -0,0 +1,48 @@
+# mode: run
+
+from cpython.number cimport PyNumber_InPlacePower
+
+def ipow(a, b, c):
+    # As far as DW can tell, calling through this C API call is the
+    # only way to actually use ternary __ipow__
+    return PyNumber_InPlacePower(a, b, c)
+
+# three-arg ipow can only work safely on Py3.8+
+# and so tests are in a separate file
+
+cdef class TwoOrThreeArgIPow:
+    """
+    >>> a = TwoOrThreeArgIPow('a')
+    >>> a**=2
+    >>> print(a)
+    a**2[None]
+    >>> print(ipow(TwoOrThreeArgIPow('a'), 'x', 'y'))
+    a**x[y]
+    """
+    cdef str name
+
+    def __init__(self, name):
+        self.name = name
+
+    def __ipow__(self, other, base=None):
+        return f"{self.name}**{other}[{base}]"
+
+
+cdef class ThreeArgIPow:
+    """
+    Note that it's not possible to detect if this is called in a 2-arg context
+    since the Python interpreter just passes None
+    >>> a = ThreeArgIPow('a')
+    >>> a**=2
+    >>> print(a)
+    a**2[None]
+    >>> print(ipow(ThreeArgIPow('a'), 'x', 'y'))
+    a**x[y]
+    """
+    cdef str name
+
+    def __init__(self, name):
+        self.name = name
+
+    def __ipow__(self, other, base):
+        return f"{self.name}**{other}[{base}]"