Add num_bytes method to CStr16 (#274)

Author: nicholasbishop

src/data_types/strs.rs

@@ -165,6 +165,11 @@ impl CStr16 {
         }
     }
 
+    /// Get the number of bytes in the string (including the trailing null character).
+    pub fn num_bytes(&self) -> usize {
+        self.0.len() * 2
+    }
+
     /// Writes each [`Char16`] as a [´char´] (4 bytes long in Rust language) into the buffer.
     /// It is up the the implementer of [`core::fmt::Write`] to convert the char to a string
     /// with proper encoding/charset. For example, in the case of [`alloc::string::String`]
@@ -236,3 +241,14 @@ impl fmt::Display for CStr16 {
         Ok(())
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_cstr16_num_bytes() {
+        let s = CStr16::from_u16_with_nul(&[65, 66, 67, 0]).unwrap();
+        assert_eq!(s.num_bytes(), 8);
+    }
+}