I am trying to find total no of nodes in a Shared-BDD using CUDD.
I have already written C Code using BuDDy-2.4 and it is running fine But when i am using CUDD instead of BuDDy, My program is showing error.
My BuDDY C File is:
//BuDDY_C Code for Node Count:
#define X1 (a&b&c&d)|(!c&d&f)|(g&!g) //Define Function-1 here
#define X2 (a&b&d&!c)|(!c&!c&d)^(g) //Define Function-2 here
#include<bdd.h>
#include<stdio.h>
#include<stdlib.h>
int main(void)
{
bdd z[2],a,b,c,d,e,f,g,h;
int i,INPUT=8,node_count,order[8]={2,5,1,6,0,4,3,7};
printf("\nGiven Variable Order:\t ");
for(i=0;i<INPUT;i++)
printf("%d \t",order[i]);
bdd_init(1000,100);
bdd_setvarnum(INPUT);
a = bdd_ithvar(order[0]); //Assign Variable order stored in order[0] to a
b = bdd_ithvar(order[1]); //Assign Variable order stored in order[1] to b
c = bdd_ithvar(order[2]); //Assign Variable order stored in order[2] to c
d = bdd_ithvar(order[3]); //Assign Variable order stored in order[3] to d
e = bdd_ithvar(order[4]); //Assign Variable order stored in order[4] to e
f = bdd_ithvar(order[5]); //Assign Variable order stored in order[5] to f
g = bdd_ithvar(order[6]); //Assign Variable order stored in order[6] to g
h = bdd_ithvar(order[7]); //Assign Variable order stored in order[7] to h
z[0]=X1;
z[1]=X2;
node_count=bdd_anodecount(z,2);
bdd_done();
printf("\n Total no of nodes are %d\n",node_count);
return 0;
}
My CUDD C Program is:
//CUDD_C Code for Node Count
#define X1 (a&b&c&d)|(!c&d&f)|(g&!g) //Define Function-1 here
#define X2 (a&b&d&!c)|(!c&!c&d)^(g) //Define Function-2 here
#include <stdio.h>
#include <stdlib.h>
#include "cudd.h"
int main(void) {
DdNode *z[2],*a,*b,*c,*d,*e,*f,*g,*h;
int i,INPUT=8,node_count,order[8]={2,5,1,6,0,4,3,7};
printf("\nGiven Variable Order:\t ");
for(i=0;i<INPUT;i++)
printf("%d \t",order[i]);
DdManager * mgr = Cudd_Init(INPUT,0,CUDD_UNIQUE_SLOTS,CUDD_CACHE_SLOTS,0);
a = Cudd_bddIthVar(mgr, order[0]); //Assign Variable order stored in order[0] to a
b = Cudd_bddIthVar(mgr, order[1]); //Assign Variable order stored in order[0] to b
c = Cudd_bddIthVar(mgr, order[2]); //Assign Variable order stored in order[0] to c
d = Cudd_bddIthVar(mgr, order[3]); //Assign Variable order stored in order[0] to d
e = Cudd_bddIthVar(mgr, order[4]); //Assign Variable order stored in order[0] to e
f = Cudd_bddIthVar(mgr, order[5]); //Assign Variable order stored in order[0] to f
g = Cudd_bddIthVar(mgr, order[6]); //Assign Variable order stored in order[0] to g
h = Cudd_bddIthVar(mgr, order[7]); //Assign Variable order stored in order[0] to h
z[0]=X1;
z[1]=X2;
Cudd_Ref(z[0]);
Cudd_Ref(z[1]);
/*-----Calculate no of nodes and number of shared nodes*/
node_count= Cudd_SharingSize( z, 2);
printf("\n Total no of nodes are %d\n",node_count);
int err = Cudd_CheckZeroRef(mgr);
Cudd_Quit(mgr);
return err;
}
But this CUDD C program is showing Error
balal#balal-HP-H710:~/Desktop/cudd-3.0.0$ g++ -o test test2_cudd.c -lbdd
test2_cudd.c: In function ‘int main()’:
test2_cudd.c:2:14: error: invalid operands of types ‘DdNode*’ and ‘DdNode*’ to binary ‘operator&’
#define X1 (a&b&c&d)|(!c&d&f)|(g&!g) //Define Function-1 here
~^~
test2_cudd.c:30:7: note: in expansion of macro ‘X1’
z[0]=X1;
^~
test2_cudd.c:2:25: error: invalid operands of types ‘bool’ and ‘DdNode*’ to binary ‘operator&’
#define X1 (a&b&c&d)|(!c&d&f)|(g&!g) //Define Function-1 here
~~^~
test2_cudd.c:30:7: note: in expansion of macro ‘X1’
z[0]=X1;
^~
test2_cudd.c:2:33: error: invalid operands of types ‘DdNode*’ and ‘bool’ to binary ‘operator&’
#define X1 (a&b&c&d)|(!c&d&f)|(g&!g) //Define Function-1 here
~^~~
test2_cudd.c:30:7: note: in expansion of macro ‘X1’
z[0]=X1;
^~
test2_cudd.c:3:14: error: invalid operands of types ‘DdNode*’ and ‘DdNode*’ to binary ‘operator&’
#define X2 (a&b&d&!c)|(!c&!c&d)^(g) //Define Function-2 here
~^~
test2_cudd.c:31:7: note: in expansion of macro ‘X2’
z[1]=X2;
^~
test2_cudd.c:3:29: error: invalid operands of types ‘int’ and ‘DdNode*’ to binary ‘operator&’
#define X2 (a&b&d&!c)|(!c&!c&d)^(g) //Define Function-2 here
~~~~~^~
test2_cudd.c:31:7: note: in expansion of macro ‘X2’
z[1]=X2;
^~
balal#balal-HP-H710:~/Desktop/cudd-3.0.0$
You are trying to use the "&" operator on BDD nodes while writing your program in C. Since C does not support operator overloading, this won't work because the "&" operator could at most mean to take the bitwise AND of the addresses, which is not what you want.
In order to compute the AND of two BDDs, you have to use the Cudd_bddAnd function. See, for instance, here for an example. Note that your macros will become a lot longer in this way and need to include local variables apart from scopes.
The alternative is to use the C++ interface to CUDD, where BDDs can be encapsulated into objects that support operator overloading.
Note that
z[0]=X1;
z[1]=X2;
Cudd_Ref(z[0]);
Cudd_Ref(z[1]);
can also potentially cause trouble. In CUDD, nodes have to be referenced with Cudd_Ref(...) before any other CUDD function is called that can create new nodes. Since your X2 macro includes operations over BDDs, this can happen. So it's best practice to Cudd_Ref(...) BDDs immediately. The following looks better:
z[0]=X1;
Cudd_Ref(z[0]);
z[1]=X2;
Cudd_Ref(z[1]);
Note that your Buddy code is also wrong for the same reason. However, since the BDD type there is defined as "typedef int BDD;" the compiler used bitwise AND and OR on the BDD node numbers instead, which is why it compiled to code that produces wrong results.
Another possibility is to use the Cython interface to CUDD that is included in the Python package dd. Installation of dd with the module dd.cudd is described here and could be summarized as
pip download dd --no-deps
tar -xzf dd-*.tar.gz
cd dd-*/
python setup.py install --fetch --cudd
This will download and build CUDD, and build and install the Cython bindings of dd to CUDD. dd has Cython bindings also to BuDDy, and those could be built similarly, with the user downloading and building BuDDy, and passing --buddy to the script setup.py.
The example code could be translated to the following Python code.
from dd import cudd as _bdd
bdd = _bdd.BDD()
bdd.declare('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h')
# /\ is conjunction in TLA+, \/ disjunction, ~ negation
X1 = bdd.add_expr('(a /\ b /\ c /\ d) \/ (~ c /\ d /\ f) \/ (g /\ ~ g)')
# note that g /\ ~ g is FALSE
X2 = bdd.add_expr('(a /\ b /\ d /\ ~ c) \/ ((~ c /\ ~ c /\ d) ^ g)')
# note that ~ c /\ ~ c is ~ c
# using the operators &, |, ! for conjunction, disjunction, and negation
X1_ = bdd.add_expr('(a & b & c & d) \/ (!c & d & f) \/ (g & !g)')
X2_ = bdd.add_expr('(a & b & d & !c) \/ ((!c & !c & d) ^ g)')
assert X1 == X1_, (X1, X1_)
assert X2 == X2_, (X2, X2_)
def descendants(roots):
"""Return nodes reachable from `roots`.
Nodes in `roots` are included.
"""
if not roots:
return set()
visited = set()
for u in roots:
_descendants(u, visited)
assert set(roots).issubset(visited), (roots, visited)
return visited
def _descendants(u, visited):
v, w = u.low, u.high
# terminal node or visited ?
if u.low is None or u in visited:
return
_descendants(v, visited)
_descendants(w, visited)
visited.add(u)
r = descendants([X1, X2])
print(len(r))
# plot diagrams of the results using GraphViz
bdd.dump('X1.pdf', [X1])
bdd.dump('X2.pdf', [X2])
The function descendants computes the set of nodes reachable from the given nodes (the nodes referenced by X1 and X2), including the given nodes. The answer for the variable order in my run is 16 nodes. The diagrams for the BDDs of the Boolean functions X1 and X2 are the following.
BDD of Boolean function X1
BDD of Boolean function X2
I wonder if it is possible to write a macro foreach on macros arguments. Here is what want to do:
#define PRINT(a) printf(#a": %d", a)
#define PRINT_ALL(...) ? ? ? THE PROBLEM ? ? ?
And possible usage:
int a = 1, b = 3, d = 0;
PRINT_ALL(a,b,d);
Here is what I achieved so far
#define FIRST_ARG(arg,...) arg
#define AFTER_FIRST_ARG(arg,...) , ##__VA_ARGS__
#define PRINT(a) printf(#a": %d", a)
#define PRINT_ALL PRINT(FIRST_ARG(__VA_ARGS__)); PRINT_ALL(AFTER_FIRST_ARG(__VA_ARGS__))
This is a recursive macro, which is illegal. And another problem with that is stop condition of recursion.
Yes, recursive macros are possible in C using a fancy workaround. The end goal is to create a MAP macro which works like this:
#define PRINT(a) printf(#a": %d", a)
MAP(PRINT, a, b, c) /* Apply PRINT to a, b, and c */
Basic Recursion
First, we need a technique for emitting something that looks like a macro
call, but isn't yet:
#define MAP_OUT
Imagine we have the following macros:
#define A(x) x B MAP_OUT (x)
#define B(x) x A MAP_OUT (x)
Evaluating the macro A (blah) produces the output text:
blah B (blah)
The preprocessor doesn't see any recursion, since the B (blah) call is
just plain text at this point, and B isn't even the name of the current
macro. Feeding this text back into the preprocessor expands the call,
producing the output:
blah blah A (blah)
Evaluating the output a third time expands the A (blah) macro, carrying
the recursion full-circle. The recursion continues as long as the caller
continues to feed the output text back into the preprocessor.
To perform these repeated evaluations, the following EVAL macro passes
its arguments down a tree of macro calls:
#define EVAL0(...) __VA_ARGS__
#define EVAL1(...) EVAL0 (EVAL0 (EVAL0 (__VA_ARGS__)))
#define EVAL2(...) EVAL1 (EVAL1 (EVAL1 (__VA_ARGS__)))
#define EVAL3(...) EVAL2 (EVAL2 (EVAL2 (__VA_ARGS__)))
#define EVAL4(...) EVAL3 (EVAL3 (EVAL3 (__VA_ARGS__)))
#define EVAL(...) EVAL4 (EVAL4 (EVAL4 (__VA_ARGS__)))
Each level multiplies the effort of the level before, evaluating the input
365 times in total. In other words, calling EVAL (A (blah)) would
produce 365 copies of the word blah, followed by a final un-evaluated B (blah). This provides the basic framework for recursion, at least within a
certain stack depth.
End Detection
The next challenge is to stop the recursion when it reaches the end of the
list.
The basic idea is to emit the following macro name instead of the normal
recursive macro when the time comes to quit:
#define MAP_END(...)
Evaluating this macro does nothing, which ends the recursion.
To actually select between the two macros, the following MAP_NEXT
macro compares a single list item against the special end-of-list marker
(). The macro returns MAP_END if the item matches, or the next
parameter if the item is anything else:
#define MAP_GET_END() 0, MAP_END
#define MAP_NEXT0(item, next, ...) next MAP_OUT
#define MAP_NEXT1(item, next) MAP_NEXT0 (item, next, 0)
#define MAP_NEXT(item, next) MAP_NEXT1 (MAP_GET_END item, next)
This macro works by placing the item next to the MAP_GET_END macro. If
doing that forms a macro call, everything moves over by a slot in the
MAP_NEXT0 parameter list, changing the output. The MAP_OUT trick
prevents the preprocessor from evaluating the final result.
Putting it All Together
With these pieces in place, it is now possible to implement useful versions
of the A and B macros from the example above:
#define MAP0(f, x, peek, ...) f(x) MAP_NEXT (peek, MAP1) (f, peek, __VA_ARGS__)
#define MAP1(f, x, peek, ...) f(x) MAP_NEXT (peek, MAP0) (f, peek, __VA_ARGS__)
These macros apply the operation f to the current list item x. They then
examine the next list item, peek, to see if they should continue or not.
The final step is to tie everything together in a top-level MAP macro:
#define MAP(f, ...) EVAL (MAP1 (f, __VA_ARGS__, (), 0))
This macro places a () marker on the end of the list, as well as an extra
0 for ANSI compliance (otherwise, the last iteration would have an illegal
0-length list). It then passes the whole thing through EVAL and
returns the result.
I have uploaded this code as a library on github for your convenience.
Using PPNARG, I wrote a set of macros to apply a macro to each argument in a macro. I call it a variadic X-macro.
/*
* The PP_NARG macro evaluates to the number of arguments that have been
* passed to it.
*
* Laurent Deniau, "__VA_NARG__," 17 January 2006, <comp.std.c> (29 November 2007).
*/
#define PP_NARG(...) PP_NARG_(__VA_ARGS__,PP_RSEQ_N())
#define PP_NARG_(...) PP_ARG_N(__VA_ARGS__)
#define PP_ARG_N( \
_1, _2, _3, _4, _5, _6, _7, _8, _9,_10, \
_11,_12,_13,_14,_15,_16,_17,_18,_19,_20, \
_21,_22,_23,_24,_25,_26,_27,_28,_29,_30, \
_31,_32,_33,_34,_35,_36,_37,_38,_39,_40, \
_41,_42,_43,_44,_45,_46,_47,_48,_49,_50, \
_51,_52,_53,_54,_55,_56,_57,_58,_59,_60, \
_61,_62,_63,N,...) N
#define PP_RSEQ_N() \
63,62,61,60, \
59,58,57,56,55,54,53,52,51,50, \
49,48,47,46,45,44,43,42,41,40, \
39,38,37,36,35,34,33,32,31,30, \
29,28,27,26,25,24,23,22,21,20, \
19,18,17,16,15,14,13,12,11,10, \
9,8,7,6,5,4,3,2,1,0
PPNARG lets us get a count of how many arguments there are. Then we append that number to the macro name and call it with the original arguments.
/* need extra level to force extra eval */
#define Paste(a,b) a ## b
#define XPASTE(a,b) Paste(a,b)
/* APPLYXn variadic X-Macro by M Joshua Ryan */
/* Free for all uses. Don't be a jerk. */
/* I got bored after typing 15 of these. */
/* You could keep going upto 64 (PPNARG's limit). */
#define APPLYX1(a) X(a)
#define APPLYX2(a,b) X(a) X(b)
#define APPLYX3(a,b,c) X(a) X(b) X(c)
#define APPLYX4(a,b,c,d) X(a) X(b) X(c) X(d)
#define APPLYX5(a,b,c,d,e) X(a) X(b) X(c) X(d) X(e)
#define APPLYX6(a,b,c,d,e,f) X(a) X(b) X(c) X(d) X(e) X(f)
#define APPLYX7(a,b,c,d,e,f,g) \
X(a) X(b) X(c) X(d) X(e) X(f) X(g)
#define APPLYX8(a,b,c,d,e,f,g,h) \
X(a) X(b) X(c) X(d) X(e) X(f) X(g) X(h)
#define APPLYX9(a,b,c,d,e,f,g,h,i) \
X(a) X(b) X(c) X(d) X(e) X(f) X(g) X(h) X(i)
#define APPLYX10(a,b,c,d,e,f,g,h,i,j) \
X(a) X(b) X(c) X(d) X(e) X(f) X(g) X(h) X(i) X(j)
#define APPLYX11(a,b,c,d,e,f,g,h,i,j,k) \
X(a) X(b) X(c) X(d) X(e) X(f) X(g) X(h) X(i) X(j) X(k)
#define APPLYX12(a,b,c,d,e,f,g,h,i,j,k,l) \
X(a) X(b) X(c) X(d) X(e) X(f) X(g) X(h) X(i) X(j) X(k) X(l)
#define APPLYX13(a,b,c,d,e,f,g,h,i,j,k,l,m) \
X(a) X(b) X(c) X(d) X(e) X(f) X(g) X(h) X(i) X(j) X(k) X(l) X(m)
#define APPLYX14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) \
X(a) X(b) X(c) X(d) X(e) X(f) X(g) X(h) X(i) X(j) X(k) X(l) X(m) X(n)
#define APPLYX15(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o) \
X(a) X(b) X(c) X(d) X(e) X(f) X(g) X(h) X(i) X(j) X(k) X(l) X(m) X(n) X(o)
#define APPLYX_(M, ...) M(__VA_ARGS__)
#define APPLYXn(...) APPLYX_(XPASTE(APPLYX, PP_NARG(__VA_ARGS__)), __VA_ARGS__)
And here are some examples with the output from gcc -E in comments.
/* Example */
#define X(a) #a,
char *list[] = {
APPLYXn(sugar,coffee,drink,smoke)
};
#undef X
/* Produces (gcc -E)
char *list[] = {
"sugar", "coffee", "drink", "smoke",
};
*/
#define c1(a) case a:
#define c2(a,b) c1(a) c1(b)
#define c3(a,b,c) c1(a) c2(b,c)
#define c4(a,b,c,d) c1(a) c3(b,c,d)
#define c_(M, ...) M(__VA_ARGS__)
#define cases(...) c_(XPASTE(c, PP_NARG(__VA_ARGS__)), __VA_ARGS__)
//cases(3,4,5,6,7)
//produces
//case 3: case 4: case 5: case 6:
#define r_(a,b) range(a,b)
#define range(a,b) a,r_(a+1,b-1)
//range(3,4)
#define ps1(a) O ## a ();
#define ps2(a,b) ps1(a) ps1(b)
#define ps3(a,b,c) ps1(a) ps2(b,c)
#define ps4(a,b,c,d) ps1(a) ps3(b,c,d)
#define ps_(M, ...) M(__VA_ARGS__)
#define ps(...) ps_(XPASTE(ps, PP_NARG(__VA_ARGS__)), __VA_ARGS__)
//ps(dup,add,sub)
This last was the motive for the whole thing. But it didn't turn out to be very useful.
Edit: many years later...
If we take a step back and reimagine the goal "apply a macro to each argument of a macro", this ia almost the same thing as an X-Macro. And I think an X-Macro can be made to do roughly the same job with a slight difference in syntax.
#define EACH_THING(X) \
X(Thing1) \
X(Thing2) \
X(OtherThing) \
/**/
Then you can write a macro that deals with each thing individually and by invoking the EACH_* with the name of the macro to use.
#define BareWord_comma(X) X ,
#define String_comma(X) #X ,
enum{ EACH_THING( BareWord_comma ) NUM_THINGS };
char*names[]={ EACH_THING( String_comma ) NULL };
Here the list of things isn't the argument list to a macro, but a sequence of macro invocations in the body of a macro. The important parts are all here, though: separating the list of things from the transformation to apply to each one.
Since you are accepting that the preprocessor has VA_ARGS (in C99, but not in the current C++ standard) you can go with P99. It has exactly what you are asking for: P99_FOR. It works without the crude ()()() syntax from BOOST. The interface is just
P99_FOR(NAME, N, OP, FUNC,...)
and you can use it with something like
#define P00_SEP(NAME, I, REC, RES) REC; RES
#define P00_VASSIGN(NAME, X, I) X = (NAME)[I]
#define MYASSIGN(NAME, ...) P99_FOR(NAME, P99_NARG(__VA_ARGS__), P00_SEP, P00_VASSIGN, __VA_ARGS__)
MYASSIGN(A, toto, tutu);
In C++ without extensions you could go for Boost.Preprocessor and it's sequences:
PRINT_ALL((a)(b)(c));
By using BOOST_PP_SEQ_FOR_EACH() on the sequence you can iterate it and easily generate code that prints them.
Untested straight-forward sample:
#define DO_PRINT(elem) std::cout << BOOST_PP_STRINGIZE(elem) << "=" << (elem) << "\n";
#define PRINT_ALL(seq) { BOOST_PP_SEQ_FOR_EACH(DO_PRINT, _, seq) }
Old question, but I thought I'd tack on a solution I came up with to use Boost.Preprocessor without the ugly (a)(b) syntax.
Header:
#include <iostream>
#include <boost\preprocessor.hpp>
#define _PPSTUFF_OUTVAR1(_var) BOOST_PP_STRINGIZE(_var) " = " << (_var) << std::endl
#define _PPSTUFF_OUTVAR2(r, d, _var) << _PPSTUFF_OUTVAR1(_var)
#define _PPSTUFF_OUTVAR_SEQ(vseq) _PPSTUFF_OUTVAR1(BOOST_PP_SEQ_HEAD(vseq)) \
BOOST_PP_SEQ_FOR_EACH(_PPSTUFF_OUTVAR2,,BOOST_PP_SEQ_TAIL(vseq))
#define OUTVAR(...) _PPSTUFF_OUTVAR_SEQ(BOOST_PP_VARIADIC_TO_SEQ(__VA_ARGS__))
Usage:
int a = 3;
char b[] = "foo";
std::cout << OUTVAR(a);
// Expands to:
//
// std::cout << "a" " = " << (a ) << std::endl ;
//
// Output:
//
// a = 3
std::cout << OUTVAR(a, b);
// Expands to:
//
// std::cout << "a" " = " << (a ) << std::endl << "b" " = " << (b) << std::endl ;
//
// Output:
//
// a = 3
// b = foo
Nice and clean.
Of course you can replace the std::endl with a comma or something if you want it all on one line.
You can use Boost.PP (after adding Boost's boost folder to your list of include directories) to get macros for this. Here's an example (tested with GCC 8.1.0):
#include <iostream>
#include <limits.h>
#include <boost/preprocessor.hpp>
#define WRITER(number,middle,elem) std::cout << \
number << BOOST_PP_STRINGIZE(middle) << elem << "\n";
#define PRINT_ALL(...) \
BOOST_PP_SEQ_FOR_EACH(WRITER, =>, BOOST_PP_VARIADIC_TO_SEQ(__VA_ARGS__))
int main (int argc, char *argv[])
{
PRINT_ALL(INT_MAX, 123, "Hello, world!");
}
Output:
2=>2147483647
3=>123
4=>Hello, world!
The BOOST_PP_VARIADIC_TO_SEQ(__VA_ARGS__) part converts the variable-argument list to Boost's traditional way of expressing multiple arguments as a single argument, which looks like this: (item1)(item2)(item3).
Not sure why it starts numbering the arguments at two. The documentation just describes the first parameter as "the next available BOOST_PP_FOR repetition".
Here's another example that defines an enum with the ability to write it as a string to an ostream, which also enables Boost's lexical_cast<string>:
#define ENUM_WITH_TO_STRING(ENUMTYPE, ...) \
enum ENUMTYPE { \
__VA_ARGS__ \
}; \
inline const char* to_string(ENUMTYPE value) { \
switch (value) { \
BOOST_PP_SEQ_FOR_EACH(_ENUM_TO_STRING_CASE, _, \
BOOST_PP_VARIADIC_TO_SEQ(__VA_ARGS__)) \
default: return nullptr; \
} \
} \
inline std::ostream& operator<<(std::ostream& os, ENUMTYPE v)\
{ return os << to_string(v); }
#define _ENUM_TO_STRING_CASE(_,__,elem) \
case elem: return BOOST_PP_STRINGIZE(elem);
ENUM_WITH_TO_STRING(Color, Red, Green, Blue)
int main (int argc, char *argv[])
{
std::cout << Red << Green << std::endl;
std::cout << boost::lexical_cast<string>(Blue) << std::endl;
}
Output:
RedGreen
Blue
The preprocessor is not powerful enough to do stuff like this. However, you don't really need the preprocessor that badly. If all you want to do is to dump variable names and their values in a convenient manner. You could have two simple macros:
#define PRINT(x) \
{ \
std::ostringstream stream; \
stream << x; \
std::cout << stream.str() << std::endl; \
}
#define VAR(v) #v << ": " << v << ", "
You could then almost use your intended usage:
int a = 1, b = 3, d = 0;
PRINT(VAR(a) << VAR(b) << VAR(d))
This prints
a: 1, b: 3, d: 0,
There are a lot of ways to make this more powerful, but this works, allows you to print non-integer values nicely and it's a rather simple solution.
I need to write some code to verify that a macro is defined but empty (not having any values). The test does not need to be in compile time.
I am attempting to write:
#if (funcprototype == "")
MY_WARN("funcprototype is empty");
#endif
the code does not compile, as funcprototype expands to empty.
If a run-time check is okay, then you can test the length of the stringized replacement:
#define REAL_STRINGIZE(x) #x
#define STRINGIZE(x) REAL_STRINGIZE(x)
if (STRINGIZE(funcprototype)[0] == '\0') {
// funcprototype expanded to an empty replacement list
}
else {
// funcprototype expanded to a non-empty replacement list
}
I don't think there is a general-case "is this macro replaced by an empty sequence of tokens" compile-time check. That is a similar problem to "is it possible to compare two sequences of tokens for equality," which is impossible to do at compile-time.
C++20 __VA_OPT__ makes this easier:
#define EMPTY(...) (true __VA_OPT__(&& false))
Then:
if (EMPTY(MY_MACRO))
With VS2013 the following works for me at pre-compile-time:
#define EXPAND(x) x
#define ARGS_dummy(...) dummy,##__VA_ARGS__
#define SELECT_from5(_1,_2,_3,_4,_5,num,...) num
#define IS_EMPTY_impl(...) EXPAND(SELECT_from5(__VA_ARGS__,0,0,0,0,1))
#define IS_EMPTY(...) EXPAND(IS_EMPTY_impl(ARGS_dummy(__VA_ARGS__)))
IS_EMPTY expands to 1 if there is no argument or the 1st argument expands to nothing, otherwise to 0.
Additional arguments are ignored.
#define x2 X
#define x1
#undef x0
IS_EMPTY(); // () -> 1
IS_EMPTY( ); // ( ) -> 1
IS_EMPTY(,); // (,) -> 1
IS_EMPTY(aaa,); // (aaa, ) -> 0
IS_EMPTY(,,); // (,,) -> -> 1
IS_EMPTY(x2); // (x2) -> (X) -> 0
IS_EMPTY(x1); // (x1) -> () -> 1
IS_EMPTY(x0); // (x0) -> 0
Now you could generate a bit mask depending on empty/nonempty parameters:
#define check_5e(a,b,c,d,e) a ## b ## c## d ## e
#define check_5d(a,b,c,d,e) check_5e(a,b,c,d,e)
#define check_5c(e,a,b,c,d) check_5d(a,b,c,d,IS_EMPTY(e))
#define check_5b(d,e,a,b,c) check_5c(e,a,b,c,IS_EMPTY(d))
#define check_5a(c,d,e,a,b) check_5b(d,e,a,b,IS_EMPTY(c))
#define check_5(b,c,d,e,a) check_5a(c,d,e,a,IS_EMPTY(b))
#define CHECK_FIVE_ARGS(a,b,c,d,e) check_5(b,c,d,e,IS_EMPTY(a))
CHECK_FIVE_ARGS(aa, , x1, x2, x0); // -> (aa,,,X,x0) -> 01100
or you can choose sub macro depending on given arguments ...
(note that VERSION_BUILD is defined but empty!)
#define VERSION_Major 3
#define VERSION_Minor 22
#define VERSION_Patch 111
#define VERSION_Build
#define VERSION_Label debug
#define MAKE_VERSION_11(a,b,c,d,e) a##.##b##.##c
#define MAKE_VERSION_10(a,b,c,d,e) a##.##b##.##c##--##e
#define MAKE_VERSION_01(a,b,c,d,e) a##.##b##.##c##-##d
#define MAKE_VERSION_00(a,b,c,d,e) a##.##b##.##c##-##d##--##e
#define MAKE_VERSION_impl2(_de) MAKE_VERSION_ ## _de
#define MAKE_VERSION_impl(_de) EXPAND(MAKE_VERSION_impl2(_de))
#define MAKE_VERSION(a,b,c,d,e) \
MAKE_VERSION_impl(IS_EMPTY(d)IS_EMPTY(e))(a,b,c,d,e)
// check 4th and 5th arg -> "MAKE_VERSION_10"
MAKE_VERSION_impl(IS_EMPTY(VERSION_Build)IS_EMPTY(VERSION_Label));
// -> 3.22.111--debug
MAKE_VERSION(VERSION_Major, VERSION_Minor, VERSION_Patch, VERSION_Build, VERSION_Label);
MAKE_VERSION(2, 3, 4, 5678, ); // -> 2.3.4-5678
MAKE_VERSION(2, 3, 4, 5678, beta); // -> 2.3.4-5678--beta
MAKE_VERSION(2, 3, 4,,); // -> 2.3.4
MAKE_VERSION(2, 3, 4, ,beta); // -> 2.3.4--beta