Remove unnecessary check in array.rs

Author: Stjepan Glavina

crossbeam-channel/src/channel.rs

@@ -58,10 +58,6 @@ pub fn unbounded<T>() -> (Sender<T>, Receiver<T>) {
 /// A special case is zero-capacity channel, which cannot hold any messages. Instead, send and
 /// receive operations must appear at the same time in order to pair up and pass the message over.
 ///
-/// # Panics
-///
-/// Panics if the capacity is greater than `usize::max_value() / 4`.
-///
 /// # Examples
 ///
 /// A channel of capacity 1:

crossbeam-channel/src/flavors/array.rs

@@ -99,24 +99,9 @@ pub struct Channel<T> {
 
 impl<T> Channel<T> {
     /// Creates a bounded channel of capacity `cap`.
-    ///
-    /// # Panics
-    ///
-    /// Panics if the capacity is not in the range `1 ..= usize::max_value() / 4`.
     pub fn with_capacity(cap: usize) -> Self {
         assert!(cap > 0, "capacity must be positive");
 
-        // Make sure there are at least two most significant bits: one to encode laps and one more
-        // to indicate that the channel is disconnected. If we can't reserve two bits, then panic.
-        // In that case, the buffer is likely too large to allocate anyway.
-        let cap_limit = usize::max_value() / 4;
-        assert!(
-            cap <= cap_limit,
-            "channel capacity is too large: {} > {}",
-            cap,
-            cap_limit
-        );
-
         // Compute constants `mark_bit` and `one_lap`.
         let mark_bit = (cap + 1).next_power_of_two();
         let one_lap = mark_bit * 2;