#define maximum_signed_value_of_type(a) \
(INTMAX_MAX >> (bitsizeof(intmax_t) - bitsizeof(a)))
+#define maximum_unsigned_value_of_type(a) \
+ (UINTMAX_MAX >> (bitsizeof(uintmax_t) - bitsizeof(a)))
+
/*
* Signed integer overflow is undefined in C, so here's a helper macro
* to detect if the sum of two integers will overflow.
#define signed_add_overflows(a, b) \
((b) > maximum_signed_value_of_type(a) - (a))
+#define unsigned_add_overflows(a, b) \
+ ((b) > maximum_unsigned_value_of_type(a) - (a))
+
#ifdef __GNUC__
#define TYPEOF(x) (__typeof__(x))
#else