gistfile1.cpp

#include <cstddef>

template<size_t n>
struct cn {
    char data[n+1];
};

template<typename id, size_t index, size_t val>
cn<val> magic(id, cn<index>, cn<val>);

#define counter_read(id) \
    (sizeof( \
        magic(id(), cn<1>(), \
        magic(id(), cn<2>(), \
        magic(id(), cn<4>(), \
        magic(id(), cn<8>(), \
        magic(id(), cn<16>(), \
        magic(id(), cn<32>(), \
        magic(id(), cn<64>(), \
        magic(id(), cn<128>(), cn<0>())))))))))-1)

#define counter_inc(id) \
    cn<counter_read(id)+1> magic(id, \
        cn<(counter_read(id)+1)&~counter_read(id)>, \
        cn<(counter_read(id)+1)&counter_read(id)>)

struct my_cnt {};

size_t const a = counter_read( my_cnt );
counter_inc( my_cnt );
counter_inc( my_cnt );
counter_inc( my_cnt );
counter_inc( my_cnt );
counter_inc( my_cnt );

size_t const b = counter_read( my_cnt );

counter_inc( my_cnt );

#include <iostream>

int main() {
    std::cout << a << ' ' << b << '\n';
    std::cout << counter_read( my_cnt ) << '\n';
}