Re: [boost] [utility] Proposal of a utility component

From: Wang Weiwei (wwwang_at_[hidden])
Date: 2006-02-04 21:40:13

hello Tobias Schwinger,

Thanks for all of your bad news. :-)

Wang Weiwei

>Wang Weiwei wrote:
>> template <typename destination_type, typename source_type>
>> destination_type force_cast(source_type s)
>> {
>> 	union 
>> 	{
>> 		source_type s;
>> [...]
>
>Looks like an almost failsafe recipe for disaster ;-).
>
>It isn't safe to use 'union' in a generic context like this one. Union members should be of POD type (BTW. that's why there is Boost.Variant).
>
>> 
>> ... a pointer to non-virtual function is actualy a normal function pointer:
>> 
>
>Another dangerous assumption:
>
>With MSVC's __thiscall calling convention (the default setting of this compiler) the this-pointer is passed in a CPU register (namely ECX) and not on the stack...
>
>
>Sorry for all the bad news,
>
>Tobias
>
>
>P.S: An array_cast that allows to change array bounds and dimensions (with checking, in contexts where possible) would have my vote (that is, if it's not in Boost already, somewhere)...
>
>
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