gh-141004: Document `Py_MATH_{E, PI, TAU}` constants (#141373)

diff --git a/Doc/c-api/float.rst b/Doc/c-api/float.rst
index b6020533a2b9d949cc10ad9e6aad4a4e3fa079a0..79de5daaa90d8f7a917a1acff7b48111251e8108 100644 (file)
--- a/Doc/c-api/float.rst
+++ b/Doc/c-api/float.rst
@@ -99,6 +99,11 @@ Floating-Point Objects
    the C11 standard ``<math.h>`` header.
 
 
+.. c:macro:: Py_MATH_E
+
+   The definition (accurate for a :c:expr:`double` type) of the :data:`math.e` constant.
+
+
 .. c:macro:: Py_MATH_El
 
    High precision (long double) definition of :data:`~math.e` constant.
@@ -106,6 +111,11 @@ Floating-Point Objects
    .. deprecated-removed:: 3.15 3.20
 
 
+.. c:macro:: Py_MATH_PI
+
+   The definition (accurate for a :c:expr:`double` type) of the :data:`math.pi` constant.
+
+
 .. c:macro:: Py_MATH_PIl
 
    High precision (long double) definition of :data:`~math.pi` constant.
@@ -113,6 +123,13 @@ Floating-Point Objects
    .. deprecated-removed:: 3.15 3.20
 
 
+.. c:macro:: Py_MATH_TAU
+
+   The definition (accurate for a :c:expr:`double` type) of the :data:`math.tau` constant.
+
+   .. versionadded:: 3.6
+
+
 .. c:macro:: Py_RETURN_NAN
 
    Return :data:`math.nan` from a function.