[C++-sig] strange behavior with respect to numeric and Boolean overloads

Roman Yakovenko roman.yakovenko at gmail.com
Tue Mar 17 06:40:14 CET 2009

On Mon, Mar 16, 2009 at 8:30 PM, Matthew Scouten (TT)
<Matthew.Scouten at tradingtechnologies.com> wrote:
> I read the linked page, but this still feels like a bug to me. Or at least a wart. Like I said, the order sensitivity I can live with, because that only effects me. But the int vs bool problem is really obnoxious. C++ can tell an int from a bool, Python can tell an int from a bool, but library between them is discarding this information.
> I agree that the best solution (from a purely technical view point) would be to rename the functions in the underlying c++ library, but I do not have control over that library and they have good reason to serve c++ users first and to resist interface breaking changes. From a UI viewpoint, the function is called foo. It foos the data that you pass to it. Having functions foo_int and foo_bool is not good style in either c++ or python.

May be you've got me wrong. I suggest to expose the function under
different names( aliases ) and than to create small function in
Python, which calls the desired one:

void foo( bool );
void foo( int );

def( "_foo_bool", (void *(bool) )( foo ) );
def( "_foo_int", (void *(int) )( foo ) );

Python code:

def foo( arg ):
    if isinstance( arg, int ):
         _foo_int( arg )
         _foo_bool( arg )


Roman Yakovenko
C++ Python language binding

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