Re: [boost] [any] Infinite loop in boost::any in boost release 1.54.0 using Visual C++ 2010

Subject: Re: [boost] [any] Infinite loop in boost::any in boost release 1.54.0 using Visual C++ 2010
From: Antony Polukhin (antoshkka_at_[hidden])
Date: 2013-10-09 07:38:33

2013/10/8 Bo Peng <elapsing_at_[hidden]>

> This very simple code:
>
> #include <boost/any.hpp>
> #include <string>
>
> const boost::any getBoolVal()
> {
>     return false;
> }
>
> int main()
> {
>     boost::any vals[] = {1.0, std::string("1m"), getBoolVal()};
> }
>
> When built using Visual C++ 2010, it will run into a infinite loop:
>
<...>

Thanks for finding that issue. I'll take care of it.

Code at line 70 in boost/any.hpp must look like this:

        template<typename ValueType>
        any(ValueType&& value
            , typename boost::disable_if<boost::is_same<any&, ValueType>
>::type* = 0 // disable if value has type `any&`
            , typename boost::disable_if<boost::is_const<ValueType>
>::type* = 0) // disable if value has type `const ValueType&&`
          : content(new holder< typename remove_reference<ValueType>::type
>(static_cast<ValueType&&>(value)))
        {
        }

Otherwise there'll be infinite loop with `any(const any&&)` and
`any::holder(const ValueType&)`, that calls for copy constructor of
ValueType.

Created a ticket for that bug: https://svn.boost.org/trac/boost/ticket/9215

-- 
Best regards,
Antony Polukhin