I ran into an odd problem when trying to compile a sketch for the Arduino Zero/M0 containing an enum definition. The Arduino IDE compiles the sketch successfully, while Visual Micro fails.

I simplified the sketch to only contain the problem:

enum class BoardState 
{ 
  Initializing = 0, 
  PowerOn, 
  Failed, 
  None 
}; 
 
void setup() {} 
 
void loop() {} 
 
void setLed(BoardState state) 
{ 
  // Do stuff here 
}

Visual Micro fails with the following error message: 

TestSketch.ino: 4:13: error: variable or field 'setLed' declared void 
   PowerOn 
  
TestSketch.ino: 4:13: error: 'BoardState' was not declared in this scope 
Error compiling project sources 
Build failed for project 'TestSketch' 

Switching between 'Visual Micro (No IDE)' and 'Arduino 1.6/1.8' makes no difference.

The problem seems to be the order of where stuff is put in the generated sketch cpp file.

Arduino IDE:

#include <Arduino.h> 
#line 1 "C:\\Users\\jonny\\Documents\\Arduino\\TestSketch\\TestSketch.ino" 
#line 1 "C:\\Users\\jonny\\Documents\\Arduino\\TestSketch\\TestSketch.ino" 
enum class BoardState 
{ 
  Initializing = 0, 
  PowerOn, 
  Failed, 
  None 
}; 
 
#line 9 "C:\\Users\\jonny\\Documents\\Arduino\\TestSketch\\TestSketch.ino" 
void setup(); 
#line 14 "C:\\Users\\jonny\\Documents\\Arduino\\TestSketch\\TestSketch.ino" 
void loop(); 
#line 19 "C:\\Users\\jonny\\Documents\\Arduino\\TestSketch\\TestSketch.ino" 
void setLed(BoardState state); 
#line 9 "C:\\Users\\jonny\\Documents\\Arduino\\TestSketch\\TestSketch.ino" 
void setup() { 
  // put your setup code here, to run once: 
 
} 
 
void loop() { 
  // put your main code here, to run repeatedly: 
 
} 
 
void setLed(BoardState state) 
{}

Visual Micro:

#include <arduino.h> 
#line 1 "C:\\Users\\jonny\\Documents\\Arduino\\TestSketch\\TestSketch.ino" 
#line 1 "C:\\Users\\jonny\\Documents\\Arduino\\TestSketch\\TestSketch.ino" 
 
// 
// 
void setLed(BoardState state); 
 
#line 1 "C:\\Users\\jonny\\Documents\\Arduino\\TestSketch\\TestSketch.ino" 
enum class BoardState 
{ 
  Initializing = 0, 
  PowerOn, 
  Failed, 
  None 
}; 
 
void setup() { 
  // put your setup code here, to run once: 
 
} 
 
void loop() { 
  // put your main code here, to run repeatedly: 
 
} 
 
void setLed(BoardState state) 
{}