Deprecate positional out argument in dpnp.maximum

Author: vlad-perevezentsev

dpnp/dpnp_iface_mathematical.py

@@ -3257,14 +3257,31 @@ def interp(x, xp, fp, left=None, right=None, period=None):
 
 """
 
-maximum = DPNPBinaryFunc(
+_maximum_impl = DPNPBinaryFunc(
     "maximum",
     ti._maximum_result_type,
     ti._maximum,
     _MAXIMUM_DOCSTRING,
 )
 
 
+@wraps(_maximum_impl)
+def maximum(*args, **kwargs):
+    """
+    Wrapper around `_maximum_impl` that emits a DeprecationWarning
+    when `out` is passed positionally.
+
+    """
+    if len(args) >= 3 and "out" not in kwargs:
+        warnings.warn(
+            "Positional `out` argument to `dpnp.maximum` is deprecated. "
+            "Please use the keyword form, e.g. `dpnp.maximum(a, b, out=c)`.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+    return _maximum_impl(*args, **kwargs)
+
+
 _MINIMUM_DOCSTRING = """
 Computes the minimum value for each element :math:`x1_i` of the input array `x1`
 relative to the respective element :math:`x2_i` of the input array `x2`.