Remove len argument from RawVec::reserve_for_push because it's always…

… equal to capacity. Also make Vec::insert use reserve_for_push.

library/alloc/src/collections/vec_deque/mod.rs

@@ -2086,10 +2086,9 @@ impl<T, A: Allocator> VecDeque<T, A> {
  // Extend or possibly remove this assertion when valid use-cases for growing the
  // buffer without it being full emerge
  debug_assert!(self.is_full());
- let old_cap = self.capacity();
- self.buf.reserve_for_push(old_cap);
+ self.buf.reserve_for_push();
  unsafe {
- self.handle_capacity_increase(old_cap);
+ self.handle_capacity_increase(self.capacity());
  }
  debug_assert!(!self.is_full());
  }

library/alloc/src/raw_vec.rs

@@ -349,8 +349,8 @@ impl<T, A: Allocator> RawVec<T, A> {
  /// oft-instantiated `Vec::push()`, which does its own capacity check.
  #[cfg(not(no_global_oom_handling))]
  #[inline(never)]
- pub fn reserve_for_push(&mut self, len: usize) {
- if let Err(err) = self.grow_amortized(len, 1) {
+ pub fn reserve_for_push(&mut self) {
+ if let Err(err) = self.grow_amortized(self.cap.0, 1) {
  handle_error(err);
  }
  }

library/alloc/src/vec/mod.rs

@@ -1547,7 +1547,7 @@ impl<T, A: Allocator> Vec<T, A> {
 
  // space for the new element
  if len == self.buf.capacity() {
- self.reserve(1);
+ self.buf.reserve_for_push();
  }
 
  unsafe {
@@ -1967,7 +1967,7 @@ impl<T, A: Allocator> Vec<T, A> {
  // This will panic or abort if we would allocate > isize::MAX bytes
  // or if the length increment would overflow for zero-sized types.
  if self.len == self.buf.capacity() {
- self.buf.reserve_for_push(self.len);
+ self.buf.reserve_for_push();
  }
  unsafe {
  let end = self.as_mut_ptr().add(self.len);