newtype.c

#include <stdio.h>

// Make a NEWTYPE
#define NT(inner,outer) \
    typedef struct \
    { \
        inner _nt_field; \
    } outer

// Declare a val of NEWTYPE
#define DECLNT(outer,name,init) outer name = { init }

// Inspect the value of a NEWTYPE
#define VALNT(x) (x)._nt_field

NT(short,INT16);
NT(int,  INT32);

INT16 increment_16(INT16 v)
{
    VALNT(v)++;
    return v;
}

INT32 increment_32(INT32 v)
{
    VALNT(v)++;
    return v;
}

int main(int argc, char * argv[])
{
    DECLNT(INT16, i_16, 15);
    DECLNT(INT32, i_32, 15);

    printf("%d\n", VALNT(i_16));
    printf("%d\n", VALNT(i_32));

    i_16 = increment_16(i_16);
    i_32 = increment_32(i_32);

    printf("%d\n", VALNT(i_16));
    printf("%d\n", VALNT(i_32));

    return 0;
}