implement (safe) min/max macros

1 files changed, 10 insertions, 0 deletions

diff --git a/src/kernel/util.h b/src/kernel/util.h
index b50810d..839aa49 100644
--- a/src/kernel/util.h
+++ b/src/kernel/util.h
@@ -8,3 +8,13 @@ void *memcpy(void *dest, const void *src, size_t n);
 void *memset(void *s, int c, size_t n);
 
 int memcmp(const void *s1, const void *s2, size_t n);
+
+// see https://gcc.gnu.org/onlinedocs/gcc/Typeof.html
+#define min(a,b) ({ \
+		typeof (a) _a = (a); \
+		typeof (b) _b = (b); \
+		_a < _b ? _a : _b; })
+#define max(a,b) ({ \
+		typeof (a) _a = (a); \
+		typeof (b) _b = (b); \
+		_a > _b ? _a : _b; })