Macro expansion in several lines

[casul]

Hi All,

I was told there were a few macro gurus on this group :)

I'm trying to define a macro that will allow me to write the following
code :
#include MY_MACRO( NAME, SPACE )
and end up with the following preprocessed code :
#include NAME.hpp

namespace SPACE {
typedef NAME ImportedNAME;
}
I have a macro that generates the correct text but since macros expand
on one unique line, what I actually end up with is the following :
#include NAME.hpp namespace SPACE { typedef NAME ImportedNAME; }
The problem with this is that the preprocessor will ignore any text
behind the filename in an #include directive, so the "namespace SPACE
...." gets skipped and meerly disappears since a preprocessor directive
has to be defined on its own line.

I can't seem to find any way to have line breaks in a macro expansion.
Is there a way to get a macro to expand on several lines ?
Thanks for your help.
BR,
Olivier.

[Frederick Gotham]

casul:

I was told there were a few macro gurus on this group :)

Sorry for the C++ code here. The query was originally posted on
comp.lang.c++, and it was I who suggested that the OP would get a better
resonse here on comp.lang.c.

Thankfully though, the query is nothing at all to do with C++, and only
concerns the C preprocessor (even though there's some C++ code in the post).

--

Frederick Gotham

[Chris Thomasson]

"casul" <ol***********@ gmail.comwrote in message
news:11******** **************@ j44g2000cwa.goo glegroups.com.. .

Hi All,

I was told there were a few macro gurus on this group :)

I'm trying to define a macro that will allow me to write the following
code :
#include MY_MACRO( NAME, SPACE )

http://groups.google.com/group/comp....382dc9a40439c7

[SM Ryan]

"casul" <ol***********@ gmail.comwrote:
# Hi All,
#
# I was told there were a few macro gurus on this group :)
#
# I'm trying to define a macro that will allow me to write the following
# code :

cpp is not a full macro processor. You will have better luck
if you use a real macro processor such as m4.

# #include MY_MACRO( NAME, SPACE )
#
#
# and end up with the following preprocessed code :
#
#
# #include NAME.hpp
#
# namespace SPACE {
# typedef NAME ImportedNAME;
# }

In m4, you can do something like
define(MY_MACRO ,`$1.hpp

namespace $2 {
typedef $1 imported$1;
}
')
and it will expand to what you want. There are also
other less arcane macro languages than m4, but you
might have to hunt harder for them.

--
SM Ryan http://www.rawbw.com/~wyrmwif/
GERBILS
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