Why does my switch/case default when using enums? - c++

Question

I have the following switch/case statement in Arduino 1.8.7 where the variable led is an integer:
switch (led) {
case ALL: {
/* do stuff */
break;
}
case LED1: {
/* do stuff */
break;
}
case LED2: {
/* do stuff */
break;
}
case LED3: {
/* do stuff */
break;
}
case LED4: {
/* do stuff */
break;
}
default: {
break;
}
}
I also have the following enum:
enum LED_References_e
{
ALL = 0,
LED1 = 1,
LED2 = 2,
LED3 = 3,
LED4 = 4
};
When using the enumerated values as cases to the statement, the statement always hits the default clause. If I substitute the enumerated values for the integers that they represent (i.e.case 0: ... case 1: ...) then the statement functions as expected.
I have tried, when using the enumerated values within the statement, to reference the enumerator as the value that the switch is performed on:
switch ((LED_References_e)led)
But this also defaults every time.
I am using another enumerator within my program and this functions correctly, however it is conditionally tested using if/else as opposed to switch/case.
My question is twofold:
Why does the switch/case statement seemingly not work with enumerated values?
What fundamental difference am I missing between if/else and switch/case?

Answer 1

Assuming Max Langhof is correct and there are other names ALL, LED1, etc... in scope at the switch so that the LED_References_e ones are shadowed, this should help:
I'm not 100% certain about the differences between standard C++ and Arduino C++, but you should be able to do the following:
enum LED_References_e
{
ALL = 0,
LED1 = 1,
LED2 = 2,
LED3 = 3,
LED4 = 4
};
switch (led) {
case LED_References_e::ALL: {
/* do stuff */
break;
}
case LED_References_e::LED1: {
/* do stuff */
break;
}
case LED_References_e::LED2: {
/* do stuff */
break;
}
case LED_References_e::LED3: {
/* do stuff */
break;
}
case LED_References_e::LED4: {
/* do stuff */
break;
}
default: {
break;
}
}
What this does is it tells the compiler you explicitly want LED1...LED4 from the LED_References_e enum.
If there are other LEDxes in the same scope, this should disambiguate.