[squid-dev] [PATCH] Deletors for std::unique_ptr fixing r14735

[Alex Rousskov]

On 07/29/2016 04:56 PM, Alex Rousskov wrote:
> On 07/29/2016 12:29 PM, Alex Rousskov wrote:
> I found two macro-free ways to do this. The so called "smart" one does
> most of the work for us, but requires repeating the function name twice,
> once with decltype() and once without:
> 
>     typedef HardFun<decltype(BIO_vfree), &BIO_vfree> BIO_Deleter;
> 
> A simpler implementation is arguably more verbose/repetitive:
> 
>     typedef HardFun<void, BIO*, &BIO_vfree> BIO_Deleter;
> 
> For comparison, the macro-based approach yields:
> 
>     CtoDeleter(BIO, BIO_vfree); // declares BIO_Deleter
> 
> And the current buggy trunk code is equivalent to this perfection:
> 
>     typedef std::function<decltype(BIO_free)> BIO_Deleter;
> 
> 
> Since the smarter implementation does not give a perfect result despite
> its tricks/complexity, I suggest going with the simpler one. The macros
> do not seem to be necessary (and HardFun offers better reuse
> possibilities than a macro if we need more hard-coded functors).


FWIW, it is easy to test the macro-free approach by redefining the macro
your patch adds to sources:

> +#define CtoDeleter(argument_type, function) \
> +typedef HardFun<void, argument_type*, &function> argument_type ## _Deleter

I tried that hack. Squid built, started, and processed a few trivial
transactions OK.

Alex.