From: Tom Widmer (tom_usenet_at_[hidden])
Date: 2005-01-11 06:11:46
Aleksey Gurtovoy wrote:
> Agoston Bejo writes:
>
>> Hello,
>>
>> how do I express through template metaprogramming or in a similar
>> way that a class is convertible to a template class for some T1?
>> I.e., the condition: "There exists some T1 such that B is
>> convertible to A<T1>".
>
>
>
> Use overload resolution. The easiest way would probably be to take
> 'is_convertible' implementation for your compiler and replace the
> overload used to detect 'To' type convertibility with with a function
> temlate accepting 'A<T1>'.
But template argument deduction will fail, won't it, since user defined
conversions aren't considered when deducing template arguments?
Obviously, if the class is derived from A<T1> for some T1, then it
should work, since the derived-to-base conversion is considered.
Tom