A compile-time const variable is referring to a thread-local static variable.
Erroneous code example:
#![feature(thread_local)]
#[thread_local]
static X: usize = 12;
const Y: usize = 2 * X;
Static and const variables can refer to other const variables but a const
variable cannot refer to a thread-local static variable. In this example,
Y cannot refer to X. To fix this, the value can be extracted as a const
and then used:
#![feature(thread_local)]
const C: usize = 12;
#[thread_local]
static X: usize = C;
const Y: usize = 2 * C;