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Help with macro (catenation)

alterecho (8)
I have some macros, as follows:
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#define CAT(st1, st2) st1 ## st2
#define STRING abc
#define MACRO CAT(STRING, d)

I expect 'MACRO' to expand to 
abcd
but it expands to 
STRINGd


Is there anyway to get 
abcd
instead?
Duthomhas (13206)
You need to add a level of indirection so the CPP parses it again.

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#include <iostream>
using namespace std;

#define CAT0(a,b) a ## b
#define CAT(a,b) CAT0(a,b)
#define STRING abc
#define ALPHABET CAT(STRING,d)

void abcd()
{
  for (char C = 'A'; C <= 'Z'; C++)
    cout << C << " ";
  cout << "\n";
}

int main()
{
  ALPHABET();
}

Hope this helps.
alterecho (8)
Works! Thanks!
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