configure.ac:
gl_PREREQ_VASNPRINTF_WITH_EXTRAS
-gl_LIBUNISTRING_LIBSOURCE([0.9], [unistdio/u8-vasnprintf.c])
+gl_LIBUNISTRING_MODULE([0.9], [unistdio/u8-vasnprintf])
Makefile.am:
+if LIBUNISTRING_COMPILE_UNISTDIO_U8_VASNPRINTF
+lib_SOURCES += unistdio/u8-vasnprintf.c
+endif
Include:
"unistdio.h"