[Cython] a problem with sizeof() return type

[Michael Abshoff]

Lisandro Dalcin wrote:
> Cython treats sizeof() as if it returns 'int', but IMHO it should be 'size_t'.

Well, you might be technically correct since that is what the C standard 
asks for, but according to various literature, i.e. for example

http://publications.gbdirect.co.uk/c_book/chapter5/sizeof_and_malloc.html

"The sizeof operator returns the size in bytes of its operand. Whether 
the result of sizeof is unsigned int or unsigned long is implementation 
defined—which is why the declaration of malloc above ducked the issue by 
omitting any parameter information; "


> Implementing this the right way would require to make Cython recognize
> 'size_t' as a native type, more or less in the way it already
> recognizes 'Py_ssize_t'. What do you think about this?
> 

Mmmh, do you want to define size_t in Cython or pull it in from 
somewhere? At least for C code that ought to be rather tricky for VS6 
for example which needs to work since we are still supporting Python 2.3 
on Windows. But you could work around the issue by defining size_t in 
Cython as either unsigned int, unsigned long or unsigned long long 
depending on the platform. But that could potentially clash with various 
C++ runtime libs.

Do you think that people will see overflow issues? I think the tradeoff 
of following the C standard here is rather high since in reality size_t 
in C is rather badly handled. And if you guys decide to follow the C 
standard here someone ought to break out Python 2.6 and VS 6 and verify 
that things are still working :)

Cheers,

Michael