Static Variables
V also supports static variables, which are like global variables, but available only inside a single unsafe function (you can look at them as namespaced globals).
Note: their use is discouraged too, for reasons similar to why globals
are discouraged. The feature is supported to enable translating existing
low level C code into V code, using v translate.
Note: the function in which you use a static variable, has to be marked
with @[unsafe]. Also unlike using globals, using static variables, do not
require you to pass the flag -enable-globals, because they can only be
read/changed inside a single function, which has full control over the
state stored in them.
Here is a small example of how static variables can be used:
@[unsafe]
fn counter() int {
mut static x := 42
// Note: x is initialised to 42, just _once_.
x++
return x
}
fn f() int {
return unsafe { counter() }
}
println(f()) // prints 43
println(f()) // prints 44
println(f()) // prints 45