---
name: "_Generic"
section: "3"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/_Generic"
---

# \_Generic(3)

type-generic selection

## NAME

\_Generic - type-generic selection

## SYNOPSIS

```
_Generic(expression, type1: e1, ... /*, default: e */);
```

## DESCRIPTION

**\_Generic**() evaluates the path of code under the type selector that is compatible with the type of the controlling *expression*, or **default:** if no type is compatible.

*expression* is not evaluated.

This is especially useful for writing type-generic macros, that will behave differently depending on the type of the argument.

## STANDARDS

C11.

## HISTORY

C11.

## EXAMPLES

The following program demonstrates how to write a replacement for the standard [**imaxabs**(3)](/imaxabs/3.md) function, which being a function can't really provide what it promises: seamlessly upgrading to the widest available type.

-

  ```
  #include <stdint.h>
  #include <stdio.h>
  #include <stdlib.h>
  #define my_imaxabs  _Generic(INTMAX_C(0),  \
      long:           labs,                  \
      long long:      llabs                  \
  /*  long long long: lllabs */              \
  )
  int
  main(void)
  {
      off_t  a;
      a = -42;
      printf("imaxabs(%jd) == %jd\n", (intmax_t) a, my_imaxabs(a));
      printf("&imaxabs == %p\n", &my_imaxabs);
      printf("&labs    == %p\n", &labs);
      printf("&llabs   == %p\n", &llabs);
      exit(EXIT_SUCCESS);
  }
  ```