[Boost-users] Re: B is_convertible to A<T> for some T

Aleksey Gurtovoy wrote:

John Maddock writes:

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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>". An example program: (Platform: VC++7.1)

I guess you want the type-trait: is_convertible.

In his case, 'to' is an unbound family of types ('A<X>' for any 'X'), so 'is_convertible' won't do it. May be we should consider getting this in the library, in some form. E.g. tweak 'is_convertible' to support something like

is_convertible >

How are you going to implement it? Overload resolution for function templates ignores user-defined conversions. -- Dave Abrahams Boost Consulting http://www.boost-consulting.com