diff --git a/library/alloc/Cargo.toml b/library/alloc/Cargo.toml
index dbdf292433bea..8d0253bd29aa2 100644
--- a/library/alloc/Cargo.toml
+++ b/library/alloc/Cargo.toml
@@ -8,7 +8,7 @@ repository = "https://github.com/rust-lang/rust.git"
 description = "The Rust core allocation and collections library"
 autotests = false
 autobenches = false
-edition = "2021"
+edition = "2024"
 
 [lib]
 test = false
diff --git a/library/core/Cargo.toml b/library/core/Cargo.toml
index edde8153aa1d2..b60826ee4e6c7 100644
--- a/library/core/Cargo.toml
+++ b/library/core/Cargo.toml
@@ -9,7 +9,7 @@ autobenches = false
 # If you update this, be sure to update it in a bunch of other places too!
 # As of 2024, it was src/tools/opt-dist, the core-no-fp-fmt-parse test and
 # the version of the prelude imported in core/lib.rs.
-edition = "2021"
+edition = "2024"
 
 [lib]
 test = false
diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
index 987fa93d59877..6e058069756f0 100644
--- a/library/core/src/lib.rs
+++ b/library/core/src/lib.rs
@@ -226,7 +226,7 @@ extern crate self as core;
 
 #[prelude_import]
 #[allow(unused)]
-use prelude::rust_2021::*;
+use prelude::rust_2024::*;
 
 #[cfg(not(test))] // See #65860
 #[macro_use]
diff --git a/library/panic_abort/Cargo.toml b/library/panic_abort/Cargo.toml
index a9d1f53761cbf..6f43ac4809a32 100644
--- a/library/panic_abort/Cargo.toml
+++ b/library/panic_abort/Cargo.toml
@@ -4,7 +4,7 @@ version = "0.0.0"
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-lang/rust.git"
 description = "Implementation of Rust panics via process aborts"
-edition = "2021"
+edition = "2024"
 
 [lib]
 test = false
diff --git a/library/panic_unwind/Cargo.toml b/library/panic_unwind/Cargo.toml
index c2abb79192e9f..d176434e06ba1 100644
--- a/library/panic_unwind/Cargo.toml
+++ b/library/panic_unwind/Cargo.toml
@@ -4,7 +4,7 @@ version = "0.0.0"
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-lang/rust.git"
 description = "Implementation of Rust panics via stack unwinding"
-edition = "2021"
+edition = "2024"
 
 [lib]
 test = false
diff --git a/library/proc_macro/Cargo.toml b/library/proc_macro/Cargo.toml
index e54a50aa15c61..72cb4e4166f8e 100644
--- a/library/proc_macro/Cargo.toml
+++ b/library/proc_macro/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "proc_macro"
 version = "0.0.0"
-edition = "2021"
+edition = "2024"
 
 [dependencies]
 std = { path = "../std" }
diff --git a/library/profiler_builtins/Cargo.toml b/library/profiler_builtins/Cargo.toml
index 230e8051602e4..e075a38daea11 100644
--- a/library/profiler_builtins/Cargo.toml
+++ b/library/profiler_builtins/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "profiler_builtins"
 version = "0.0.0"
-edition = "2021"
+edition = "2024"
 
 [lib]
 test = false
diff --git a/library/rustc-std-workspace-alloc/Cargo.toml b/library/rustc-std-workspace-alloc/Cargo.toml
index 049ca3e46b57d..5a177808d1bd8 100644
--- a/library/rustc-std-workspace-alloc/Cargo.toml
+++ b/library/rustc-std-workspace-alloc/Cargo.toml
@@ -5,7 +5,7 @@ license = 'MIT OR Apache-2.0'
 description = """
 Hack for the compiler's own build system
 """
-edition = "2021"
+edition = "2024"
 
 [lib]
 path = "lib.rs"
diff --git a/library/rustc-std-workspace-core/Cargo.toml b/library/rustc-std-workspace-core/Cargo.toml
index ff5cfcbd64144..9315c08a4d199 100644
--- a/library/rustc-std-workspace-core/Cargo.toml
+++ b/library/rustc-std-workspace-core/Cargo.toml
@@ -5,7 +5,7 @@ license = 'MIT OR Apache-2.0'
 description = """
 Hack for the compiler's own build system
 """
-edition = "2021"
+edition = "2024"
 
 [lib]
 path = "lib.rs"
diff --git a/library/rustc-std-workspace-std/Cargo.toml b/library/rustc-std-workspace-std/Cargo.toml
index 3a1dc2a02b557..f70994e1f8868 100644
--- a/library/rustc-std-workspace-std/Cargo.toml
+++ b/library/rustc-std-workspace-std/Cargo.toml
@@ -5,7 +5,7 @@ license = 'MIT OR Apache-2.0'
 description = """
 Hack for the compiler's own build system
 """
-edition = "2021"
+edition = "2024"
 
 [lib]
 path = "lib.rs"
diff --git a/library/std/Cargo.toml b/library/std/Cargo.toml
index 0ec167c2d1618..19fe0cdd7aeb3 100644
--- a/library/std/Cargo.toml
+++ b/library/std/Cargo.toml
@@ -6,7 +6,7 @@ version = "0.0.0"
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-lang/rust.git"
 description = "The Rust Standard Library"
-edition = "2021"
+edition = "2024"
 autobenches = false
 
 [lib]
diff --git a/library/std/src/keyword_docs.rs b/library/std/src/keyword_docs.rs
index 5ac3dbc3e9852..c07c391892d80 100644
--- a/library/std/src/keyword_docs.rs
+++ b/library/std/src/keyword_docs.rs
@@ -1064,7 +1064,7 @@ mod move_keyword {}
 /// ```rust,compile_fail,E0502
 /// let mut v = vec![0, 1];
 /// let mut_ref_v = &mut v;
-/// ##[allow(unused)]
+/// # #[allow(unused)]
 /// let ref_v = &v;
 /// mut_ref_v.push(2);
 /// ```
diff --git a/library/std/src/os/windows/process.rs b/library/std/src/os/windows/process.rs
index fa65a7c51bfa0..a084f452e55d0 100644
--- a/library/std/src/os/windows/process.rs
+++ b/library/std/src/os/windows/process.rs
@@ -531,7 +531,7 @@ impl<'a> ProcThreadAttributeListBuilder<'a> {
     ///     pub Y: i16,
     /// }
     ///
-    /// extern "system" {
+    /// unsafe extern "system" {
     ///     fn CreatePipe(
     ///         hreadpipe: *mut HANDLE,
     ///         hwritepipe: *mut HANDLE,
diff --git a/library/sysroot/Cargo.toml b/library/sysroot/Cargo.toml
index 0f6fa2d291ab3..ec6ae31507e05 100644
--- a/library/sysroot/Cargo.toml
+++ b/library/sysroot/Cargo.toml
@@ -3,7 +3,7 @@ cargo-features = ["public-dependency"]
 [package]
 name = "sysroot"
 version = "0.0.0"
-edition = "2021"
+edition = "2024"
 
 # this is a dummy crate to ensure that all required crates appear in the sysroot
 [dependencies]
diff --git a/library/test/Cargo.toml b/library/test/Cargo.toml
index 241ef324b0088..2a32a7dd76eed 100644
--- a/library/test/Cargo.toml
+++ b/library/test/Cargo.toml
@@ -3,7 +3,7 @@ cargo-features = ["public-dependency"]
 [package]
 name = "test"
 version = "0.0.0"
-edition = "2021"
+edition = "2024"
 
 [dependencies]
 getopts = { version = "0.2.21", features = ['rustc-dep-of-std'] }
diff --git a/library/unwind/Cargo.toml b/library/unwind/Cargo.toml
index 66e8d1a3ffe5f..da60924c2b419 100644
--- a/library/unwind/Cargo.toml
+++ b/library/unwind/Cargo.toml
@@ -3,7 +3,7 @@ name = "unwind"
 version = "0.0.0"
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-lang/rust.git"
-edition = "2021"
+edition = "2024"
 include = [
   '/libunwind/*',
 ]
diff --git a/library/windows_targets/Cargo.toml b/library/windows_targets/Cargo.toml
index 94d7c8210647c..705c9e0438119 100644
--- a/library/windows_targets/Cargo.toml
+++ b/library/windows_targets/Cargo.toml
@@ -2,7 +2,7 @@
 name = "windows-targets"
 description = "A drop-in replacement for the real windows-targets crate for use in std only."
 version = "0.0.0"
-edition = "2021"
+edition = "2024"
 
 [features]
 # Enable using raw-dylib for Windows imports.
diff --git a/library/windows_targets/src/lib.rs b/library/windows_targets/src/lib.rs
index 939fab7d5fe62..c7d158584ebd8 100644
--- a/library/windows_targets/src/lib.rs
+++ b/library/windows_targets/src/lib.rs
@@ -12,7 +12,7 @@ pub macro link {
     ($library:literal $abi:literal $($link_name:literal)? $(#[$doc:meta])? fn $($function:tt)*) => (
         #[cfg_attr(not(target_arch = "x86"), link(name = $library, kind = "raw-dylib", modifiers = "+verbatim"))]
         #[cfg_attr(target_arch = "x86", link(name = $library, kind = "raw-dylib", modifiers = "+verbatim", import_name_type = "undecorated"))]
-        extern $abi {
+        unsafe extern $abi {
             $(#[link_name=$link_name])?
             pub fn $($function)*;
         }
@@ -26,7 +26,7 @@ pub macro link {
         // libraries below by using an empty extern block. This works because extern blocks are not
         // connected to the library given in the #[link] attribute.
         #[link(name = "kernel32")]
-        extern $abi {
+        unsafe extern $abi {
             $(#[link_name=$link_name])?
             pub fn $($function)*;
         }
diff --git a/tests/mir-opt/gvn_clone.{impl#0}-clone.GVN.diff b/tests/mir-opt/gvn_clone.{impl#0}-clone.GVN.diff
index 8d5991872e180..2a672e829707f 100644
--- a/tests/mir-opt/gvn_clone.{impl#0}-clone.GVN.diff
+++ b/tests/mir-opt/gvn_clone.{impl#0}-clone.GVN.diff
@@ -55,16 +55,16 @@
       bb3: {
           StorageDead(_9);
 -         _0 = AllCopy { a: move _2, b: move _5, c: move _8 };
+-         StorageDead(_10);
 +         _0 = copy (*_1);
++         nop;
           StorageDead(_8);
-          StorageDead(_5);
-          StorageDead(_2);
--         StorageDead(_10);
 -         StorageDead(_7);
--         StorageDead(_4);
-+         nop;
 +         nop;
+          StorageDead(_5);
+-         StorageDead(_4);
 +         nop;
+          StorageDead(_2);
           return;
       }
   }
diff --git a/tests/mir-opt/instsimplify/combine_clone_of_primitives.{impl#0}-clone.InstSimplify-after-simplifycfg.panic-abort.diff b/tests/mir-opt/instsimplify/combine_clone_of_primitives.{impl#0}-clone.InstSimplify-after-simplifycfg.panic-abort.diff
index d0b50c597c4f7..5f9a8fe9547dd 100644
--- a/tests/mir-opt/instsimplify/combine_clone_of_primitives.{impl#0}-clone.InstSimplify-after-simplifycfg.panic-abort.diff
+++ b/tests/mir-opt/instsimplify/combine_clone_of_primitives.{impl#0}-clone.InstSimplify-after-simplifycfg.panic-abort.diff
@@ -53,12 +53,12 @@
       bb3: {
           StorageDead(_9);
           _0 = MyThing::<T> { v: move _2, i: move _5, a: move _8 };
-          StorageDead(_8);
-          StorageDead(_5);
-          StorageDead(_2);
           StorageDead(_10);
+          StorageDead(_8);
           StorageDead(_7);
+          StorageDead(_5);
           StorageDead(_4);
+          StorageDead(_2);
           return;
       }
   }
diff --git a/tests/mir-opt/instsimplify/combine_clone_of_primitives.{impl#0}-clone.InstSimplify-after-simplifycfg.panic-unwind.diff b/tests/mir-opt/instsimplify/combine_clone_of_primitives.{impl#0}-clone.InstSimplify-after-simplifycfg.panic-unwind.diff
index b8f4f348530a3..0a02c2d4c0f1b 100644
--- a/tests/mir-opt/instsimplify/combine_clone_of_primitives.{impl#0}-clone.InstSimplify-after-simplifycfg.panic-unwind.diff
+++ b/tests/mir-opt/instsimplify/combine_clone_of_primitives.{impl#0}-clone.InstSimplify-after-simplifycfg.panic-unwind.diff
@@ -53,12 +53,12 @@
       bb3: {
           StorageDead(_9);
           _0 = MyThing::<T> { v: move _2, i: move _5, a: move _8 };
-          StorageDead(_8);
-          StorageDead(_5);
-          StorageDead(_2);
           StorageDead(_10);
+          StorageDead(_8);
           StorageDead(_7);
+          StorageDead(_5);
           StorageDead(_4);
+          StorageDead(_2);
           return;
       }
   
diff --git a/tests/run-make/core-no-fp-fmt-parse/rmake.rs b/tests/run-make/core-no-fp-fmt-parse/rmake.rs
index 3586922f28ecb..a790ada40db85 100644
--- a/tests/run-make/core-no-fp-fmt-parse/rmake.rs
+++ b/tests/run-make/core-no-fp-fmt-parse/rmake.rs
@@ -5,7 +5,7 @@ use run_make_support::{rustc, source_root};
 
 fn main() {
     rustc()
-        .edition("2021")
+        .edition("2024")
         .arg("-Dwarnings")
         .crate_type("rlib")
         .input(source_root().join("library/core/src/lib.rs"))
diff --git a/tests/ui/macros/std-2024-macros.rs b/tests/ui/macros/std-2024-macros.rs
new file mode 100644
index 0000000000000..453c7ee16e5a6
--- /dev/null
+++ b/tests/ui/macros/std-2024-macros.rs
@@ -0,0 +1,13 @@
+// Tests a small handful of macros in the standard library how they handle the
+// new behavior introduced in 2024 that allows `const{}` expressions.
+
+//@ check-pass
+
+fn main() {
+    assert_eq!(0, const { 0 });
+    assert_eq!(const { 0 }, const { 0 });
+    assert_eq!(const { 0 }, 0);
+
+    let _: Vec<Vec<String>> = vec![const { vec![] }];
+    let _: Vec<Vec<String>> = vec![const { vec![] }; 10];
+}