use std::ops::{
    RangeFull,
    RangeFrom,
    RangeTo,
    Range,
};

/// **RangeArgument** is implemented by Rust's built-in range types, produced
/// by range syntax like `..`, `a..`, `..b` or `c..d`.
pub trait RangeArgument {
    #[inline]
    #[doc(hidden)]
    /// Start index (inclusive)
    fn start(&self) -> Option<usize> { None }
    #[inline]
    #[doc(hidden)]
    /// End index (exclusive)
    fn end(&self) -> Option<usize> { None }
}


impl RangeArgument for RangeFull {}

impl RangeArgument for RangeFrom<usize> {
    #[inline]
    fn start(&self) -> Option<usize> { Some(self.start) }
}

impl RangeArgument for RangeTo<usize> {
    #[inline]
    fn end(&self) -> Option<usize> { Some(self.end) }
}

impl RangeArgument for Range<usize> {
    #[inline]
    fn start(&self) -> Option<usize> { Some(self.start) }
    #[inline]
    fn end(&self) -> Option<usize> { Some(self.end) }
}


use std::ops::{
    RangeFull,
    RangeFrom,
    RangeTo,
    Range,
};

/// **RangeArgument** is implemented by Rust's built-in range types, produced
/// by range syntax like `..`, `a..`, `..b` or `c..d`.
pub trait RangeArgument {
    #[doc(hidden)]
    /// Start index (inclusive)
    fn start(&self) -> Option<usize> { None }
    #[doc(hidden)]
    /// End index (exclusive)
    fn end(&self) -> Option<usize> { None }
}


impl RangeArgument for RangeFull {}

impl RangeArgument for RangeFrom<usize> {
    fn start(&self) -> Option<usize> { Some(self.start) }
}

impl RangeArgument for RangeTo<usize> {
    fn end(&self) -> Option<usize> { Some(self.end) }
}

impl RangeArgument for Range<usize> {
    fn start(&self) -> Option<usize> { Some(self.start) }
    fn end(&self) -> Option<usize> { Some(self.end) }
}


--- 
+++ 
@@ -8,9 +8,11 @@
 /// **RangeArgument** is implemented by Rust's built-in range types, produced
 /// by range syntax like `..`, `a..`, `..b` or `c..d`.
 pub trait RangeArgument {
+    #[inline]
     #[doc(hidden)]
     /// Start index (inclusive)
     fn start(&self) -> Option<usize> { None }
+    #[inline]
     #[doc(hidden)]
     /// End index (exclusive)
     fn end(&self) -> Option<usize> { None }
@@ -20,15 +22,19 @@
 impl RangeArgument for RangeFull {}
 
 impl RangeArgument for RangeFrom<usize> {
+    #[inline]
     fn start(&self) -> Option<usize> { Some(self.start) }
 }
 
 impl RangeArgument for RangeTo<usize> {
+    #[inline]
     fn end(&self) -> Option<usize> { Some(self.end) }
 }
 
 impl RangeArgument for Range<usize> {
+    #[inline]
     fn start(&self) -> Option<usize> { Some(self.start) }
+    #[inline]
     fn end(&self) -> Option<usize> { Some(self.end) }
 }
 
Make sure the methods on RangeArgument can be inlined
