Trait alloc::slice::Concat  [−][src]
Expand description
Helper trait for [T]::concat.
Note: the Item type parameter is not used in this trait,
but it allows impls to be more generic.
Without it, we get this error:
error[E0207]: the type parameter `T` is not constrained by the impl trait, self type, or predica
   --> src/liballoc/slice.rs:608:6
    |
608 | impl<T: Clone, V: Borrow<[T]>> Concat for [V] {
    |      ^ unconstrained type parameterThis is because there could exist V types with multiple Borrow<[_]> impls,
such that multiple T types would apply:
pub struct Foo(Vec<u32>, Vec<String>);
impl std::borrow::Borrow<[u32]> for Foo {
    fn borrow(&self) -> &[u32] { &self.0 }
}
impl std::borrow::Borrow<[String]> for Foo {
    fn borrow(&self) -> &[String] { &self.1 }
}Associated Types
Required methods
Implementations on Foreign Types
Note: str in Concat<str> is not meaningful here.
This type parameter of the trait only exists to enable another impl.