Patch #1675423: PyComplex_AsCComplex() now tries to convert an object

to complex using its __complex__() method before falling back to the
__float__() method. Therefore, the functions in the cmath module now
can operate on objects that define a __complex__() method.
 (backport)

1 files changed, 8 insertions, 1 deletions

diff --git a/Doc/lib/libcmath.tex b/Doc/lib/libcmath.tex
index 54e0cdb1fe..f8aa45bb4a 100644
--- a/Doc/lib/libcmath.tex
+++ b/Doc/lib/libcmath.tex
@@ -5,7 +5,14 @@
 \modulesynopsis{Mathematical functions for complex numbers.}
 
 This module is always available.  It provides access to mathematical
-functions for complex numbers.  The functions are:
+functions for complex numbers.  The functions in this module accept
+integers, floating-point numbers or complex numbers as arguments.
+They will also accept any Python object that has either a
+\method{__complex__} or a \method{__float__} method: these methods are
+used to convert the object to a complex or floating-point number, respectively, and
+the function is then applied to the result of the conversion.
+
+The functions are:
 
 \begin{funcdesc}{acos}{x}
 Return the arc cosine of \var{x}.