"useless type qualifier" error
c, struct
Solution
You don't get an error, just a warning.
And that applies to how you declare your `struct cal`: it is not volatile by itself; the volatile only applies to a concrete variable definition.
So in `static struct cal cal`, your variable `cal` is just `static`, but not `volatile`.
In that sense, the `volatile` declaration is, as the warning says, useless.
Problem
I get the following error with the following code. I tried to figure out where the problem is over Google, but I didn't find anything helpful. ``` Compiling /home/tectu/projects/resources/chibios/ext/lcd/touchpad.c In file included from /home/tectu/projects/resources/chibios/ext/lcd/touchpad.c:1:0: /home/tectu/projects/resources/chibios/ext/lcd/touchpad.h:17:1: warning: useless type qualifier in empty declaration [enabled by default] ``` Here's the the code from line 12 to line 17 from `touchpad.h`: ``` volatile struct cal { float xm; float ym; float xn; float yn; }; ``` And here's how I use this struct inside `touchpad.c`: ``` static struct cal cal = { 1, 1, 0, 0 }; ``` Can anyone show me the light? :D