snippet once "Include header once only guard"
#ifndef ${1:`!p snip.rv = re.sub(r'[^A-Za-z0-9]+','_', snip.fn).upper()`}
#define $1
snippet once "Include header once only guard"
#ifndef ${1:`!p snip.rv = re.sub(r'[^A-Za-z0-9]+','_', snip.fn).upper()`}
#define $1