Specialize implementations

Implementations in stdlib are now optimized as they were before.

13 files changed, 23 insertions, 0 deletions

diff --git a/compiler/rustc_ast/src/lib.rs b/compiler/rustc_ast/src/lib.rs
index 0f6e0fb8825..14ecf27813d 100644
--- a/compiler/rustc_ast/src/lib.rs
+++ b/compiler/rustc_ast/src/lib.rs
@@ -17,6 +17,8 @@
 #![feature(iter_zip)]
 #![feature(label_break_value)]
 #![feature(nll)]
+#![feature(min_specialization)]
+#![feature(trusted_step)]
 #![recursion_limit = "256"]
 
 #[macro_use]
diff --git a/compiler/rustc_hir/src/lib.rs b/compiler/rustc_hir/src/lib.rs
index 6a12c917436..7f3c410b1ec 100644
--- a/compiler/rustc_hir/src/lib.rs
+++ b/compiler/rustc_hir/src/lib.rs
@@ -7,6 +7,8 @@
 #![cfg_attr(bootstrap, feature(extended_key_value_attributes))]
 #![feature(in_band_lifetimes)]
 #![feature(once_cell)]
+#![feature(min_specialization)]
+#![feature(trusted_step)]
 #![recursion_limit = "256"]
 
 #[macro_use]
diff --git a/compiler/rustc_index/src/lib.rs b/compiler/rustc_index/src/lib.rs
index 4c73b7bf612..04d62391c02 100644
--- a/compiler/rustc_index/src/lib.rs
+++ b/compiler/rustc_index/src/lib.rs
@@ -6,6 +6,7 @@
 #![feature(unboxed_closures)]
 #![feature(test)]
 #![feature(fn_traits)]
+#![feature(trusted_step)]
 
 pub mod bit_set;
 pub mod vec;
diff --git a/compiler/rustc_index/src/vec.rs b/compiler/rustc_index/src/vec.rs
index 9cf6756a090..440e0943d6e 100644
--- a/compiler/rustc_index/src/vec.rs
+++ b/compiler/rustc_index/src/vec.rs
@@ -204,6 +204,9 @@ macro_rules! newtype_index {
             }
         }
 
+        // Safety: The implementation of `Step` upholds all invariants.
+        unsafe impl ::std::iter::TrustedStep for $type {}
+
         impl From<$type> for u32 {
             #[inline]
             fn from(v: $type) -> u32 {
diff --git a/compiler/rustc_infer/src/lib.rs b/compiler/rustc_infer/src/lib.rs
index f3e5830c198..6b452bca8e7 100644
--- a/compiler/rustc_infer/src/lib.rs
+++ b/compiler/rustc_infer/src/lib.rs
@@ -22,6 +22,8 @@
 #![feature(never_type)]
 #![feature(in_band_lifetimes)]
 #![feature(control_flow_enum)]
+#![feature(min_specialization)]
+#![feature(trusted_step)]
 #![recursion_limit = "512"] // For rustdoc
 
 #[macro_use]
diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs
index 7e85f5d5de2..6f97716e2e0 100644
--- a/compiler/rustc_middle/src/lib.rs
+++ b/compiler/rustc_middle/src/lib.rs
@@ -50,6 +50,7 @@
 #![feature(associated_type_defaults)]
 #![feature(iter_zip)]
 #![feature(thread_local_const_init)]
+#![feature(trusted_step)]
 #![recursion_limit = "512"]
 
 #[macro_use]
diff --git a/compiler/rustc_mir/src/lib.rs b/compiler/rustc_mir/src/lib.rs
index 010da247b2e..647c368d2bb 100644
--- a/compiler/rustc_mir/src/lib.rs
+++ b/compiler/rustc_mir/src/lib.rs
@@ -31,6 +31,7 @@ Rust MIR: a lowered representation of Rust.
 #![feature(option_get_or_insert_default)]
 #![feature(once_cell)]
 #![feature(control_flow_enum)]
+#![feature(trusted_step)]
 #![recursion_limit = "256"]
 
 #[macro_use]
diff --git a/compiler/rustc_mir_build/src/lib.rs b/compiler/rustc_mir_build/src/lib.rs
index e4a71b52b78..99b854ff066 100644
--- a/compiler/rustc_mir_build/src/lib.rs
+++ b/compiler/rustc_mir_build/src/lib.rs
@@ -10,6 +10,8 @@
 #![feature(bool_to_option)]
 #![feature(iter_zip)]
 #![feature(once_cell)]
+#![feature(min_specialization)]
+#![feature(trusted_step)]
 #![recursion_limit = "256"]
 
 #[macro_use]
diff --git a/compiler/rustc_passes/src/lib.rs b/compiler/rustc_passes/src/lib.rs
index fdcb2293a41..4803148eba9 100644
--- a/compiler/rustc_passes/src/lib.rs
+++ b/compiler/rustc_passes/src/lib.rs
@@ -10,6 +10,8 @@
 #![feature(in_band_lifetimes)]
 #![feature(iter_zip)]
 #![feature(nll)]
+#![feature(min_specialization)]
+#![feature(trusted_step)]
 #![recursion_limit = "256"]
 
 #[macro_use]
diff --git a/compiler/rustc_query_system/src/lib.rs b/compiler/rustc_query_system/src/lib.rs
index be72baefb9e..7df3804c986 100644
--- a/compiler/rustc_query_system/src/lib.rs
+++ b/compiler/rustc_query_system/src/lib.rs
@@ -6,6 +6,7 @@
 #![feature(iter_zip)]
 #![feature(min_specialization)]
 #![feature(stmt_expr_attributes)]
+#![feature(trusted_step)]
 
 #[macro_use]
 extern crate tracing;
diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs
index 0301b364591..39b7b36b853 100644
--- a/compiler/rustc_span/src/lib.rs
+++ b/compiler/rustc_span/src/lib.rs
@@ -21,6 +21,7 @@
 #![feature(nll)]
 #![feature(min_specialization)]
 #![feature(thread_local_const_init)]
+#![feature(trusted_step)]
 
 #[macro_use]
 extern crate rustc_macros;
diff --git a/compiler/rustc_target/src/lib.rs b/compiler/rustc_target/src/lib.rs
index 48ace9b65b6..a40de5ef18e 100644
--- a/compiler/rustc_target/src/lib.rs
+++ b/compiler/rustc_target/src/lib.rs
@@ -14,6 +14,8 @@
 #![feature(never_type)]
 #![feature(associated_type_bounds)]
 #![feature(exhaustive_patterns)]
+#![feature(min_specialization)]
+#![feature(trusted_step)]
 
 use std::path::{Path, PathBuf};
 
diff --git a/compiler/rustc_type_ir/src/lib.rs b/compiler/rustc_type_ir/src/lib.rs
index 0dbcd483c45..3f4c8a72f1d 100644
--- a/compiler/rustc_type_ir/src/lib.rs
+++ b/compiler/rustc_type_ir/src/lib.rs
@@ -1,3 +1,6 @@
+#![feature(min_specialization)]
+#![feature(trusted_step)]
+
 #[macro_use]
 extern crate bitflags;
 #[macro_use]