diff --git a/Marlin/src/core/macros.h b/Marlin/src/core/macros.h index 96439b090..f760ce820 100644 --- a/Marlin/src/core/macros.h +++ b/Marlin/src/core/macros.h @@ -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 static inline constexpr void NOLESS(V& v, const N n) { + if (v < n) v = n; + } + template static inline constexpr void NOMORE(V& v, const N n) { + if (v > n) v = n; + } + template 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__