Resolve old TODO (#175)

* Resolve old TODO

* Bump MSRV to 1.57

Author: bugadani

.circleci/config.yml

@@ -1,6 +1,6 @@
 target_steps: &target_steps
   docker:
-    - image: cimg/rust:1.56.0
+    - image: cimg/rust:1.57.0
   steps:
     - checkout
     - restore_cache:

CHANGELOG.md

@@ -6,6 +6,10 @@
 
 ## [Unreleased] - ReleaseDate
 
+### Changed
+
+- **(breaking)** [#175](https://github.com/jamwaffles/ssd1306/pull/175) Increased MSRV to 1.57.0
+
 ## [0.7.1] - 2022-08-15
 
 ### Added

Cargo.toml

@@ -11,6 +11,7 @@ repository = "https://github.com/jamwaffles/ssd1306"
 version = "0.7.1"
 edition = "2018"
 exclude = [ "build.rs", "build.sh", "memory.x", "doc", "*.jpg", "*.png", "*.bmp" ]
+rust-version = "1.57"
 
 [badges]
 circle-ci = { repository = "jamwaffles/ssd1306", branch = "master" }

src/brightness.rs

@@ -40,6 +40,11 @@ impl Brightness {
     /// `contrast` sets the value used in the `0x81 Set Contrast Control` command and must be
     /// between 0 and 255. See section 10.1.7 of the SSD1306 datasheet for more information.
     const fn custom(precharge: u8, contrast: u8) -> Self {
+        debug_assert!(
+            0 < precharge && precharge <= 15,
+            "Precharge value must be between 1 and 15"
+        );
+
         Self {
             precharge,
             contrast,

src/lib.rs

@@ -343,12 +343,6 @@ where
 
     /// Change the display brightness.
     pub fn set_brightness(&mut self, brightness: Brightness) -> Result<(), DisplayError> {
-        // Should be moved to Brightness::new once conditions can be used in const functions
-        debug_assert!(
-            0 < brightness.precharge && brightness.precharge <= 15,
-            "Precharge value must be between 1 and 15"
-        );
-
         Command::PreChargePeriod(1, brightness.precharge).send(&mut self.interface)?;
         Command::Contrast(brightness.contrast).send(&mut self.interface)
     }