From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Tue, 11 Nov 2025 10:13:59 +0000 (+0300)
Subject: gh-141004: document Py_INFINITY and Py_NAN macros (#141145)
X-Git-Tag: v3.15.0a2~114
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d69447445cbacf7537bf59c5c683a3b17060312d;p=thirdparty%2FPython%2Fcpython.git

gh-141004: document Py_INFINITY and Py_NAN macros (#141145)

Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>
---

diff --git a/Doc/c-api/float.rst b/Doc/c-api/float.rst
index 9e703a46445d..eae4792af7d2 100644
--- a/Doc/c-api/float.rst
+++ b/Doc/c-api/float.rst
@@ -78,6 +78,24 @@ Floating-Point Objects
    Return the minimum normalized positive float *DBL_MIN* as C :c:expr:`double`.
 
 
+.. c:macro:: Py_INFINITY
+
+   This macro expands a to constant expression of type :c:expr:`double`, that
+   represents the positive infinity.
+
+   On most platforms, this is equivalent to the :c:macro:`!INFINITY` macro from
+   the C11 standard ``<math.h>`` header.
+
+
+.. c:macro:: Py_NAN
+
+   This macro expands a to constant expression of type :c:expr:`double`, that
+   represents a quiet not-a-number (qNaN) value.
+
+   On most platforms, this is equivalent to the :c:macro:`!NAN` macro from
+   the C11 standard ``<math.h>`` header.
+
+
 .. c:macro:: Py_MATH_El
 
    High precision (long double) definition of :data:`~math.e` constant.