#include <stdio.h>
#include <stdlib.h>

#define template_function_name(type) \
  function_##type

#define template_function_declare(type) \
  type function_##type(type a, type b)  \
  {                                     \
    return a + b;                       \
  }

#define template_function_internal(type) \
    type: template_function_name(type)

template_function_declare(int);
template_function_declare(float);
template_function_declare(double);

#define function(a, b)                 \
  _Generic(                            \
    a,                                 \
    template_function_internal(int),   \
    template_function_internal(float), \
    template_function_internal(double) \
  )(a, b)

int main(void)
{
  printf("`int`    + `int`    = %d\n", function(10000, 10000));
  printf("`float`  + `float`  = %f\n", function((float)10000.0, (float)10000.0));
  printf("`double` + `double` = %f\n", function(10000.0, 10000.0));

  return EXIT_SUCCESS;
}