Converted the series of function-like macros in Arduino.h into constexpr functions in the case of C++. Required in order to avoid conflicts to C++ stdlib.

Author: KOLANICH

Diff for: cores/arduino/Arduino.h

@@ -93,6 +93,39 @@ void yield(void);
 }; // extern "C"
 #endif
 
+#if defined(__cplusplus)
+template <typename T> constexpr T min(const T a, const T b){
+  return a<b?a:b;
+}
+
+template <typename T> constexpr T max(const T a, const T b){
+  return a>b?a:b;
+}
+
+template <typename T> constexpr T abs(const T x){
+  return x>0?x:-x;
+}
+
+template <typename T> constexpr T constrain(const T amt, const T low, const T high){
+  return amt<low?low:(amt>high?high:amt);
+}
+
+template <typename T> constexpr T round(const T x){
+  return x>=0?static_cast<long>(x+0.5):static_cast<long>(x-0.5);
+}
+
+template <typename T> constexpr T radians(const T deg){
+  return deg * DEG_TO_RAD;
+}
+
+template <typename T> constexpr T degrees(const T rad){
+  return rad * RAD_TO_DEG;
+}
+
+template <typename T> constexpr T sq(const T x){
+  return x * x;
+}
+#else
 #define min(a,b) ((a)<(b)?(a):(b))
 #define max(a,b) ((a)>(b)?(a):(b))
 #define abs(x) ((x)>0?(x):-(x))
@@ -101,10 +134,39 @@ void yield(void);
 #define radians(deg) ((deg)*DEG_TO_RAD)
 #define degrees(rad) ((rad)*RAD_TO_DEG)
 #define sq(x) ((x)*(x))
+#endif
 
 #define interrupts() sei()
 #define noInterrupts() cli()
 
+#if defined(__cplusplus)
+constexpr unsigned long clockCyclesPerMicrosecond(){
+  return F_CPU / 1000000L;
+}
+
+template <typename T> constexpr T clockCyclesToMicroseconds(const T a){
+  return a / clockCyclesPerMicrosecond();
+}
+
+template <typename T> constexpr T microsecondsToClockCycles(const T a){
+  return a * clockCyclesPerMicrosecond();
+}
+
+constexpr unsigned char lowByte(uint16_t w){
+  return w & 0xff;
+}
+
+constexpr unsigned char highByte(uint16_t w){
+  return w >> 8;
+}
+
+template <typename T>
+constexpr bool bitRead(T value, unsigned char bit){
+  return (value >> bit) & 0x01;
+}
+
+#else
+
 #define clockCyclesPerMicrosecond() ( F_CPU / 1000000L )
 #define clockCyclesToMicroseconds(a) ( (a) / clockCyclesPerMicrosecond() )
 #define microsecondsToClockCycles(a) ( (a) * clockCyclesPerMicrosecond() )
@@ -113,6 +175,8 @@ void yield(void);
 #define highByte(w) ((uint8_t) ((w) >> 8))
 
 #define bitRead(value, bit) (((value) >> (bit)) & 0x01)
+#endif
+
 #define bitSet(value, bit) ((value) |= (1UL << (bit)))
 #define bitClear(value, bit) ((value) &= ~(1UL << (bit)))
 #define bitToggle(value, bit) ((value) ^= (1UL << (bit)))