Re: [boost] [preprocessor] Sequences vs. All Other Data Structures

Subject: Re: [boost] [preprocessor] Sequences vs. All Other Data Structures
From: Nathan Ridge (zeratul976_at_[hidden])
Date: 2012-05-02 04:07:02

> I guess this thread was largely about communicating some things
> to Microsoft. I have an item to add to the list. I'm not sure of the
> terminology for this but it is supported in some of the newer versions
> of g++, but not in the version of VS 11 that I have. The code shown
> below is available here:
> http://webEbenezer.net/misc/direct.tar.bz2
>.

>
>
> This snippet is from cmwAmbassador.cc
> #ifdef ENDIAN_BIG
> , byteOrder(most_significant_first)
> #else
> , byteOrder(least_significant_first)
> #endif
>
> and this from cmwAmbassador.hh
>
> #ifdef ENDIAN_BIG
> ::cmw::ReceiveBufferTCPCompressed<LeastSignificantFirst> cmwBuf; #else
> ::cmw::ReceiveBufferTCPCompressed<SameFormat> cmwBuf; #endif
>
> uint8_t const byteOrder;
>
>
> I want to rewrite that as the following in the .hh file.
>
> #ifdef ENDIAN_BIG
> ::cmw::ReceiveBufferTCPCompressed<LeastSignificantFirst> cmwBuf;
> uint8_t const byteOrder = most_significant_first;
> #else
> ::cmw::ReceiveBufferTCPCompressed<SameFormat> cmwBuf;
> uint8_t const byteOrder = least_significant_first; #endif
>
> and be able to get rid of the ifdef in the .cc file. Microsoft:
> please add support for this and let me know when it is available.

This looks like a use of non-static data member initializers, a C++11
feature. GCC support for this feature has been added in 4.7, and VC does
not yet support it. This is one of the many C++11 features in which VC
lags behind GCC (others are variadic templates, uniform initialization,
delegating constructors, user-defined literals, and many others).

I agree that it would be nice if MS got VC up to speed on C++11, but
what does this have to do with the preprocessor?

Regards,
Nate