Using a recursive macro to write the arguments of a function

Question

Is it possible to use a recursive macro to write as many function arguments as required. For example:

void foo( const char (&row1)[3] , const char (&row2)[3] , const char (&row3)[3] )
{
}

void foo( const char (&row1)[3] , const char (&row2)[3] , const char (&row3)[3] , const char (&row4)[3] , const char (&row5)[3] , const char (&row6)[3] )
{
}

I am aware that variadic templates were introduced to solve problems like this but I am limited to C++98 ATM.

score 5 · Answer 1 · edited May 23 '17 at 11:50

5

You can have a look at the boost::preprocessor library which gives you a whole preprocessing toolkit. It provides preprocessor metaprogramming tools including repetition and recursion.

You can see an example in this answer.

edited May 23 '17 at 11:50

Community

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answered Sep 13 '13 at 18:16

David

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Thanks. What part of the preprocessor library should I pay close attention to? I am not at all familiar with the library and but like to solve the problem ASAP. – Olumide Sep 13 '13 at 19:00
@Olumide you could take a look at ENUM_BINARY_PARAMS http://www.boost.org/doc/libs/1_54_0/libs/preprocessor/doc/ref/enum_binary_params.html – David Sep 13 '13 at 20:13

score 0 · Answer 2 · answered Sep 13 '13 at 18:20

Macros can't be recursive, since macro expansion won't expand the name of a macro in the process of being expanded. C++11 did introduce the concept of macros with a variable number of arguments, using __VA_ARGS__, but I don't know too much about it. (I use very few macros.)

score 0 · Answer 3 · answered Sep 13 '13 at 18:25

0

Traditionally, the developer would create a set of macros, each with a different number of arguments:

#define foo1(arg1)
#define foo2(arg1, arg2)
#define foo3(arg1, arg2, arg3)
...

answered Sep 13 '13 at 18:25

josh poley

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Using a recursive macro to write the arguments of a function

3 Answers3