(Issue rust-num#10) Fixed things pointed out by cuviper.

src/lib.rs

@@ -978,14 +978,6 @@ impl<T: Clone + Integer + Signed> Signed for Ratio<T> {
     }
 }
 
-#[cfg(feature = "std")]
-use std::string::String;
-
-#[cfg(feature = "std")]
-trait AsDecimal {
-    fn as_decimal(&self, usize) -> String;
-}
-
 // String conversions
 impl<T> fmt::Display for Ratio<T>
 where
@@ -1002,44 +994,43 @@ where
 }
 
 #[cfg(feature = "std")]
-impl<T> AsDecimal for Ratio<T> where
+use std::string::String;
+
+#[cfg(feature = "std")]
+impl<T> Ratio<T> where
     T: fmt::Display
         + Clone
-        + Eq
         + FromPrimitive
         + Integer
-        + Pow<usize, Output = T>
         + Signed
-        + std::string::ToString,
 {
     /// Generates decimal approximation to a specified precision as a String.
-    fn as_decimal(&self, precision: usize) -> String {
-        if self.denom.is_one() {
-            self.numer.to_string()
+    pub fn as_decimal(&self, precision: usize) -> String {
+        use traits::pow;
+        use std::string::ToString;
+        let ten_pow_prec = pow(T::from_usize(10).unwrap(), precision);
+        let rounded = (self.clone() * &ten_pow_prec).round();
+        let minus = rounded < Zero::zero();
+        let trunc = &((&rounded / &ten_pow_prec).trunc().to_integer());
+        let tail = &(rounded % ten_pow_prec).abs().to_integer();
+        let mut ret_val = String::from("");
+        if tail.is_zero() {
+            ret_val.push_str(&trunc.to_string());
         } else {
-            let _10_pow_prec = T::from_usize(10).unwrap().pow(precision);
-            let rounded = (self.clone() * &_10_pow_prec).round();
-            let minus = rounded < Zero::zero();
-            let trunc = &((&rounded / &_10_pow_prec).trunc().to_integer());
-            let tail = &(rounded % _10_pow_prec).abs().to_integer();
-            if tail.is_zero() {
-                trunc.to_string()
-            } else {
-                let mut ret_val = String::from(if minus { "-" } else { "" });
-                ret_val.push_str(&trunc.to_string());
-                ret_val.push_str(".");
-                let tail_strarr = &tail.to_string();
-                let tail_length = &tail_strarr.chars().count();
-                let tail_zeroes = if tail_length < &precision {
-                    // If rust >= 1.16.0 - we can simply use repeat.
-                    // "0".repeat(precision - tail_length)
-                    (0..(precision - tail_length)).map(|_| "0").collect::<String>()
-                } else { String::from("") };
-                ret_val.push_str(&tail_zeroes);
-                ret_val.push_str(&tail.to_string());
-                ret_val
-            }
-        }
+            if minus { ret_val.push_str("-") };
+            ret_val.push_str(&trunc.to_string());
+        }
+        ret_val.push_str(".");
+        let tail_strarr = &tail.to_string();
+        let tail_length = &tail_strarr.chars().count();
+        let tail_zeroes = if *tail_length < precision {
+            // If rust >= 1.16.0 - we can simply use repeat.
+            // "0".repeat(precision - tail_length)
+            (0..(precision - tail_length)).map(|_| "0").collect::<String>()
+        } else { String::from("") };
+        ret_val.push_str(&tail_zeroes);
+        ret_val.push_str(&tail.to_string());
+        ret_val
     }
 }
 
@@ -1602,17 +1593,16 @@ mod test {
     #[test]
     #[cfg(feature = "std")]
     fn test_as_decimal() {
-        use AsDecimal;
         use std::string::ToString;
-        assert_eq!(_2.as_decimal(2), "2".to_string());
+        assert_eq!(_2.as_decimal(2), "2.00".to_string());
         assert_eq!(_1_2.as_decimal(2), "0.50".to_string());
         assert_eq!(_3_2.as_decimal(1), "1.5".to_string());
         assert_eq!(_NEG1_2.as_decimal(2), "-0.50".to_string());
         assert_eq!(_NEG2_3.as_decimal(3), "-0.667".to_string());
         assert_eq!(_1_8.as_decimal(2), "0.13".to_string());
         assert_eq!(_NEG1_8.as_decimal(4), "-0.1250".to_string());
         assert_eq!(_99999_1000.as_decimal(3), "99.999".to_string());
-        assert_eq!(_NEG99999_1000.as_decimal(1), "-100".to_string());
+        assert_eq!(_NEG99999_1000.as_decimal(1), "-100.0".to_string());
     }
 
     mod arith {