Add no_std to the crate

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name          = "ansi_colours"
 description   = "true-colour ↔ ANSI terminal palette converter"
-version       = "1.1.0"
+version       = "1.1.1"
 readme        = "README.md"
 authors       = ["Michał Nazarewicz <mina86@mina86.com>"]
 keywords      = ["ansi", "terminal", "color", "rgb"]

src/lib.rs

@@ -67,6 +67,8 @@
 //! }
 //! ```
 
+#![no_std]
+
 pub(crate) mod ansi256;
 #[cfg(test)]
 mod test;

src/test.rs

@@ -107,10 +107,13 @@ fn test_to_ansi_approx() {
 /// purpose simply update the checksum in this test.
 #[test]
 fn from_rgb_checksum() {
-    let mut vec = Vec::with_capacity(1 << 24);
+    let mut buf = [0; 1 << 12];
+    let mut checksum = 0;
     for rgb in 0..(1 << 24) {
-        vec.push(crate::ansi256_from_rgb(rgb));
+        buf[rgb % buf.len()] = crate::ansi256_from_rgb(rgb as u32);
+        if rgb % buf.len() == buf.len() - 1 {
+            checksum = crc64::crc64(checksum, &buf);
+        }
     }
-    let checksum = crc64::crc64(0, vec.as_slice());
     assert_eq!(3373856917329536106, checksum);
 }