Implement CAM16 to XYZ and make CAM16 support an optional feature

.github/workflows/ci.yml

@@ -31,15 +31,17 @@ jobs:
       - name: find-crate check
         run: cargo check -v -p palette --no-default-features --features "std find-crate"
       - name: Default check
-        run: cargo check -v --workspace --exclude no_std_test
-      - run: cargo test -v
+        run: cargo check -v -p palette
+      - name: Full check
+        run: cargo check -v -p palette --all-features
+      - run: cargo test -v -p palette --all-features
       - name: Test features
         shell: bash
         working-directory: palette
         run: bash ../scripts/test_features.sh
       - name: "Test #[no_std]"
         if: ${{ runner.os == 'Linux' && matrix.toolchain == 'nightly' }}
-        run: cargo build -v --package no_std_test --features nightly --target thumbv6m-none-eabi
+        run: cargo build -v --package no_std_test --all-features --target thumbv6m-none-eabi
   miri:
     name: Miri tests
     runs-on: ubuntu-latest

.vscode/settings.json

@@ -3,9 +3,10 @@
         "random",
         "serializing",
         "bytemuck",
-        "wide"
+        "wide",
+        "cam16"
     ],
     "rust-analyzer.imports.granularity.enforce": true,
     "rust-analyzer.imports.granularity.group": "crate",
     "rust-analyzer.imports.group.enable": true
-}
+}

no_std_test/Cargo.toml

@@ -14,6 +14,7 @@ bench = false
 
 [features]
 nightly = []
+all_features = ["palette/libm", "palette/named_from_str", "palette/cam16"]
 
 [dependencies.libc]
 version = "0.2"
@@ -22,4 +23,3 @@ default-features = false
 [dependencies.palette]
 path = "../palette"
 default-features = false
-features = ["libm", "named_from_str"]

palette/Cargo.toml

@@ -28,6 +28,7 @@ build = "build/main.rs"
 
 [features]
 default = ["named_from_str", "std", "approx"]
+cam16 = ["palette_derive/cam16"]
 named_from_str = ["named", "phf"]
 named = []
 random = ["rand"]