refactor(test_suite): use Range: const Iterator and const_for

Author: yvt

src/r3_test_suite/src/kernel_benchmarks/timer_start.rs

@@ -41,11 +41,10 @@ impl<System: SupportedSystem> AppInner<System> {
         let timers = {
             let mut timers = MaybeUninit::uninit_array();
 
-            let mut i = 0;
-            // `for` is unusable in `const fn` [ref:const_for]
-            while i < timers.len() {
+            // `[T]::iter_mut` is unusable in `const fn` [ref:const_slice_iter]
+            // `core::array::from_fn` is not `const fn` [ref:const_array_from_fn]
+            for i in 0..timers.len() {
                 timers[i] = MaybeUninit::new(StaticTimer::define().start(|| {}).finish(b));
-                i += 1;
             }
 
             unsafe { MaybeUninit::array_assume_init(timers) }

src/r3_test_suite/src/kernel_tests/compute_atomics_round_robin.rs

@@ -143,17 +143,16 @@ impl<System: SupportedSystem> App<System> {
 
         let mut tasks = [None; NUM_TASKS];
 
-        // `for` is unusable in `const fn` [ref:const_for]
-        let mut i = 0;
-        while i < NUM_TASKS {
+        // `[T]::iter_mut` is unusable in `const fn` [ref:const_slice_iter]
+        // `core::array::from_fn` is not `const fn` [ref:const_array_from_fn]
+        for i in 0..NUM_TASKS {
             tasks[i] = Some(
                 StaticTask::define()
                     .active(true)
                     .start((i, worker_body::<System, D>))
                     .priority(2)
                     .finish(b),
             );
-            i += 1;
         }
 
         // `<[_; 2]>::map` is unusable in `const fn` [ref:const_array_map]

src/r3_test_suite/src/kernel_tests/compute_round_robin.rs

@@ -63,9 +63,9 @@ impl<System: SupportedSystem> App<System> {
 
         let mut tasks = [None; NUM_TASKS];
 
-        // `for` is unusable in `const fn` [ref:const_for]
-        let mut i = 0;
-        while i < NUM_TASKS {
+        // `[T]::iter_mut` is unusable in `const fn` [ref:const_slice_iter]
+        // `core::array::from_fn` is not `const fn` [ref:const_array_from_fn]
+        for i in 0..NUM_TASKS {
             let task_state = if i == 0 {
                 // Reuse the storage
                 task_state.borrow_mut()
@@ -88,7 +88,6 @@ impl<System: SupportedSystem> App<System> {
                     .priority(3)
                     .finish(b),
             );
-            i += 1;
         }
 
         // `<[_; 4]>::map` is unusable in `const fn` [ref:const_array_map]

src/r3_test_suite/src/kernel_tests/time_stress.rs

@@ -23,15 +23,12 @@ impl<System: SupportedSystem> App<System> {
     where
         C: ~const traits::CfgTask<System = System> + ~const traits::CfgEventGroup,
     {
-        let mut i = 0;
-        // `for` is unusable in `const fn` [ref:const_for]
-        while i < TASKS.len() {
+        for i in 0..TASKS.len() {
             StaticTask::define()
                 .start((i, task_body::<System, D>))
                 .priority(0)
                 .active(true)
                 .finish(b);
-            i += 1;
         }
 
         StaticTask::define()

src/r3_test_suite/src/lib.rs

@@ -2,6 +2,7 @@
 #![feature(const_fn_floating_point_arithmetic)]
 #![feature(const_maybe_uninit_uninit_array)]
 #![feature(maybe_uninit_array_assume_init)]
+#![feature(const_intoiterator_identity)]
 #![feature(maybe_uninit_uninit_array)]
 #![feature(cfg_target_has_atomic)]
 #![feature(const_transmute_copy)]
@@ -12,7 +13,9 @@
 #![feature(array_windows)]
 #![feature(const_option)]
 #![feature(cell_update)]
+#![feature(const_iter)]
 #![feature(decl_macro)]
+#![feature(const_for)]
 #![feature(is_sorted)]
 #![deny(unsafe_op_in_unsafe_fn)]
 #![allow(clippy::eq_op)] // we want to test `PartialEq` implementations

src/r3_test_suite/src/utils/trig.rs

@@ -46,16 +46,13 @@ pub const fn sincos(theta: f64) -> (f64, f64) {
     let mut x = 1.0;
     let mut y = 0.0;
 
-    // `for` is unusable in `const fn` [ref:const_for]
-    let mut i = 0;
-    while i < 32 {
+    for i in 0..32 {
         if (theta_i & (1u32 << i)) != 0 {
             let (x2, y2) = (x, y);
             let (sin, cos) = TABLE[i];
             x = x2 * cos - y2 * sin;
             y = x2 * sin + y2 * cos;
         }
-        i += 1;
     }
 
     if neg {