Re: [Boost-users] [intrusive_ptr] Strange ternary op behavior with MSVC14

Subject: Re: [Boost-users] [intrusive_ptr] Strange ternary op behavior with MSVC14
From: Stephan Bergmann (sbergman_at_[hidden])
Date: 2015-08-11 05:39:59

On 08/11/2015 10:27 AM, TONGARI J wrote:
> template<class T>
> struct wrapper
> {
>      wrapper() = default;
>
>      wrapper(boost::intrusive_ptr<T> const& p) : _p(p) {}
>
>      boost::intrusive_ptr<T> const& get_ptr() const
>      {
> #if 0
>          // This is OK.
>          if (_p)
>              return _p;
>          return nullptr;
> #else
>          // Strange behavior.
>          return _p ? _p : nullptr;
> #endif
>      }

In both cases, you return a reference to a temporary, incurring 
undefined behavior.