[boost] [system] virtual ~error_category

Subject: [boost] [system] virtual ~error_category
From: Peter Dimov (lists_at_[hidden])
Date: 2018-02-12 19:13:23

The virtual destructor of error_category creates problems for 
constexpr-ification because it makes the class non-literal.

I can't think of a scenario in which we need the destructor to be virtual. 
It's probably virtual for "guideline" reasons - the class has virtual 
functions. But does it really need to be? Error categories aren't destroyed 
via a pointer to base. They are, in fact, static instances, not destroyed at 
all, except on program exit.

Can anyone think of a case in which error_category needs the virtual 
destructor?