Re: [review][fixed_string] FixedString review results

From: Gavin Lambert (boost_at_[hidden])
Date: 2019-12-16 03:25:16

On 16/12/2019 13:45, Krystian Stasiowski wrote:
>> 22. Store size (as capacity-size) in the last char of the data array, so
>> as to save one memory byte.
> 
> This has been implemented, there will be a macro to enable/disable this.

Using a macro to alter storage layout is a bad idea unless done very 
carefully (eg. the macro selects between implementations in different 
namespaces, or with different template parameters).

Otherwise you risk subtle ABI breakage problems if it (accidentally or 
otherwise) ends up defined differently in different translation units 
that are later linked together.

Anything that alters the ABI layout of the type needs to be reflected in 
the type's mangled signature in some way.

Otherwise, just pick something and stick with it; don't make it 
configurable.