Re: Test for endian using MPL or PP(Wave?)

----- Original Message ----- From: "David Abrahams" Newsgroups: gmane.comp.lib.boost.user Sent: Wednesday, April 23, 2003 2:48 AM Subject: Re: Test for endian using MPL or PP(Wave?)

"Mike Wilson" writes:

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Thanks for that - I'll look into it.

----- Original Message ----- From: "Ryan Barrett" Newsgroups: gmane.comp.lib.boost.user Sent: Monday, April 21, 2003 10:48 PM Subject: Re: Test for endian using MPL or PP(Wave?)

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check out boost's template metaprogramming library...i won't guarantee anything, but you might be able to contort it to do what you need.

http://boost.org/libs/mpl/doc/index.html

Don't bother. Endian-ness is fundamentally a property of memory layout. You can't discover anything about the layout of bits in memory at compile-time (and certainly not using the preprocessor), since you can't dereference a pointer at compile-time. The only way to discover endian-ness is to write an integer type to memory and read it back out as a sequence of chars. I thought so, but the doc was informative.

Of course, some platforms supply headers which will tell you about their endian-ness...

I think I saw a BOOST_BIG_ENDIAN_TARGET mentioned in the archives, but no such luck in my 1.29 sources. Thanks.