gh-119613: Soft deprecate Py_IS_NAN/INFINITY/FINITE (#119701)

skirpichev · hugovk · erlend-aasland · web-flow · commit 0cdc5c8d5446 · 2024-05-29T10:45:14.000Z
Co-authored-by: Hugo van Kemenade &lt;1324225+hugovk@users.noreply.github.com&gt;
Co-authored-by: Erlend E. Aasland &lt;erlend.aasland@protonmail.com&gt;
Co-authored-by: Victor Stinner &lt;vstinner@python.org&gt;
diff --git a/Doc/whatsnew/3.14.rst b/Doc/whatsnew/3.14.rst
@@ -231,6 +231,12 @@ Porting to Python 3.14
 Deprecated
 ----------
 
+* Macros :c:macro:`!Py_IS_NAN`, :c:macro:`!Py_IS_INFINITY`
+  and :c:macro:`!Py_IS_FINITE` are :term:`soft deprecated`,
+  use instead :c:macro:`!isnan`, :c:macro:`!isinf` and
+  :c:macro:`!isfinite` available from :file:`math.h`
+  since C99.  (Contributed by Sergey B Kirpichev in :gh:`119613`.)
+
 Removed
 -------
 
diff --git a/Include/pymath.h b/Include/pymath.h
@@ -29,14 +29,17 @@
 
 // Py_IS_NAN(X)
 // Return 1 if float or double arg is a NaN, else 0.
+// Soft deprecated since Python 3.14, use isnan() instead.
 #define Py_IS_NAN(X) isnan(X)
 
 // Py_IS_INFINITY(X)
 // Return 1 if float or double arg is an infinity, else 0.
+// Soft deprecated since Python 3.14, use isinf() instead.
 #define Py_IS_INFINITY(X) isinf(X)
 
 // Py_IS_FINITE(X)
 // Return 1 if float or double arg is neither infinite nor NAN, else 0.
+// Soft deprecated since Python 3.14, use isfinite() instead.
 #define Py_IS_FINITE(X) isfinite(X)
 
 // Py_INFINITY: Value that evaluates to a positive double infinity.
diff --git a/Misc/NEWS.d/next/C API/2024-05-29-09-21-37.gh-issue-119613.J2xfrC.rst b/Misc/NEWS.d/next/C API/2024-05-29-09-21-37.gh-issue-119613.J2xfrC.rst
@@ -0,0 +1,2 @@
+Macros ``Py_IS_NAN``, ``Py_IS_INFINITY`` and ``Py_IS_FINITE``
+are :term:`soft deprecated`.
