Include the header in every file needed as usual:
```
-#include "<ext-func-name>.h"
+#include "${function}.h"
```
In the file chosen for the function implementation:
```
-#define <EXT-FUNC-NAME>_IMPLEMENTATION
-#include "<ext-func-name.h>"
+#define LCE_${FUNCTION}_IMPLEMENTATION
+#include "${function}.h>"
```
By default, the header won't have any stdlib includes, change that with:
```
-#define <EXT-FUNC-NAME>_INCLUDE_LIBC
+#define LCE_${FUNCTION}_INCLUDE_LIBC
```
Or disable function, type and variable override with:
```
-#define HAVE_<EXT-FUNC-NAME>
+#define HAVE_${FUNCTION}
```
### Specifics
permuting, defining those enables it per function (GNU behaviour, can still be disabled at runtime by setting `$POSIXLY_CORRECT`):
```
-#define GETOPT_PERMUTE_ARGS
-#define GETOPT_LONG_PERMUTE_ARGS
-#define GETOPT_LONG_ONLY_PERMUTE_ARGS
+#define LCE_GETOPT_PERMUTE_ARGS
+#define LCE_GETOPT_LONG_PERMUTE_ARGS
+#define LCE_GETOPT_LONG_ONLY_PERMUTE_ARGS
```
---