Re: [Boost-users] [hash][vc-7_1] warning on boost::hash<std::size_t> [was Re: [multi_index] function object as key extractor?]

From: Filip Konvička (filip.konvicka_at_[hidden])
Date: 2007-03-15 11:36:18

> Do you mean hash_value(unsigned int) is also invoked when using
> boost::hash<std::size_t>, right?
>   
Yes.
>> There are other variants of this function, taking bool, int, etc. as the
>> argument, but no size_t.
>>     
> This is correct, because std::size_t is a typedef to some builtin
> unsigned integer type.
>   
Unfortunately, this is not in the case....

typedef __w64 unsigned int   size_t;

This is due to /Wp64, as you have correctly guessed.
> a) look in your stdlib headers (most likely in stddef.h) how size_t is
> defined?
>   
See above.
> b) try the following snippet and report whether the warning persists?
>
>   #include <cstddef>
>
>   void foo(unsigned int){}
>
>   int main()
>   {
>     std::size_t x=0;
>     foo(x);
>   }
>   
This exhibits the same problem. Both are fine without /Wp64. So I think 
that adding /Wp64 means that the warning should be turned off.
> Thank you!
>   
Thank you!

Cheers,
Filip