Improve NOMORE, NOLESS, and LIMIT macros

This commit is contained in:
etagle 2018-05-16 17:16:07 -03:00 committed by Scott Lahteine
parent 40d7e12827
commit 06fd4d7b28

View File

@ -91,10 +91,50 @@
#define SIGN(a) ((a>0)-(a<0))
#define IS_POWER_OF_2(x) ((x) && !((x) & ((x) - 1)))
// Macros to contrain values
#define NOLESS(v,n) do{ if (v < n) v = n; }while(0)
#define NOMORE(v,n) do{ if (v > n) v = n; }while(0)
#define LIMIT(v,n1,n2) do{ if (v < n1) v = n1; else if (v > n2) v = n2; }while(0)
// Macros to constrain values
// Avoid double evaluation of arguments to NOMORE/NOLESS/LIMIT
#undef NOMORE
#undef NOLESS
#undef LIMIT
#ifdef __cplusplus
// C++11 solution that is standards compliant.
template <class V, class N> static inline constexpr void NOLESS(V& v, const N n) {
if (v < n) v = n;
}
template <class V, class N> static inline constexpr void NOMORE(V& v, const N n) {
if (v > n) v = n;
}
template <class V, class N1, class N2> static inline constexpr void LIMIT(V& v, const N1 n1, const N2 n2) {
if (v < n1) v = n1;
else if (v > n2) v = n2;
}
#else
// Using GCC extensions, but Travis GCC version does not like it and gives
// "error: statement-expressions are not allowed outside functions nor in template-argument lists"
#define NOLESS(v, n) \
do { \
__typeof__(n) _n = (n); \
if (v < _n) v = _n; \
} while(0)
#define NOMORE(v, n) \
do { \
__typeof__(n) _n = (n); \
if (v > _n) v = _n; \
} while(0)
#define LIMIT(v, n1, n2) \
do { \
__typeof__(n1) _n1 = (n1); \
__typeof__(n2) _n2 = (n2); \
if (v < _n1) v = _n1; \
else if (v > _n2) v = _n2; \
} while(0)
#endif
// Macros to support option testing
#define _CAT(a, ...) a ## __VA_ARGS__