round bug

[Jake]

I inserted a round function into my code and it complained during compilation. It turns out that the wiring.h has a #define round, that conflicts with the c round function.

The following code will not compile until the line with the round function is commented out.

// comment out the next line and all works
double yd = round(sqrt(PI));
float yf = roundf(sqrt(PI));
long int yi =roundl(sqrt(PI));

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}

The wiring.h file has the command on line 80

#define round(x) ({ \
  typeof(x) _x = (x); \
  (_x>=0) ? (long)(_x+0.5) : (long)(_x-0.5); \
})

 

[PaulStoffregen]

Yeah, this is a tough one. Should Teensy strive for compatibility with Arduino or pure C. Usually Arduino compatibility is the goal, when the 2 are at odds with each other.

 

[MichaelMeissner]

And note, the macro in wiring.h produces the wrong answers if the value of x is larger than what can be stored into a long variable, or is -0.0.

 

[Frank B]

It compiles with adding

#include "wiring.h"
#undef round

to the top of your sketch.