From 0bcec3760467995fb08e55ef6e7be697d13490a5 Mon Sep 17 00:00:00 2001
From: arferreira <arfs.antonio@gmail.com>
Date: Wed, 11 Feb 2026 20:37:45 -0500
Subject: [PATCH] Improve write! and writeln! error when called without
 destination

---
 library/core/src/macros/mod.rs                   | 6 ++++++
 tests/ui/macros/write-missing-destination.rs     | 7 +++++++
 tests/ui/macros/write-missing-destination.stderr | 8 ++++++++
 3 files changed, 21 insertions(+)
 create mode 100644 tests/ui/macros/write-missing-destination.rs
 create mode 100644 tests/ui/macros/write-missing-destination.stderr

diff --git a/library/core/src/macros/mod.rs b/library/core/src/macros/mod.rs
index 3176f3c06709..156ff846cbeb 100644
--- a/library/core/src/macros/mod.rs
+++ b/library/core/src/macros/mod.rs
@@ -611,6 +611,9 @@ macro_rules! write {
     ($dst:expr, $($arg:tt)*) => {
         $dst.write_fmt($crate::format_args!($($arg)*))
     };
+    ($($arg:tt)*) => {
+        compile_error!("requires a destination and format arguments, like `write!(dest, \"format string\", args...)`")
+    };
 }
 
 /// Writes formatted data into a buffer, with a newline appended.
@@ -649,6 +652,9 @@ macro_rules! writeln {
     ($dst:expr, $($arg:tt)*) => {
         $dst.write_fmt($crate::format_args_nl!($($arg)*))
     };
+    ($($arg:tt)*) => {
+        compile_error!("requires a destination and format arguments, like `writeln!(dest, \"format string\", args...)`")
+    };
 }
 
 /// Indicates unreachable code.
diff --git a/tests/ui/macros/write-missing-destination.rs b/tests/ui/macros/write-missing-destination.rs
new file mode 100644
index 000000000000..02e0e096a907
--- /dev/null
+++ b/tests/ui/macros/write-missing-destination.rs
@@ -0,0 +1,7 @@
+// Check that `write!` without a destination gives a helpful error message.
+// See https://github.com/rust-lang/rust/issues/152493
+
+fn main() {
+    write!("S");
+    //~^ ERROR requires a destination and format arguments
+}
diff --git a/tests/ui/macros/write-missing-destination.stderr b/tests/ui/macros/write-missing-destination.stderr
new file mode 100644
index 000000000000..3136191ca17a
--- /dev/null
+++ b/tests/ui/macros/write-missing-destination.stderr
@@ -0,0 +1,8 @@
+error: requires a destination and format arguments, like `write!(dest, "format string", args...)`
+  --> $DIR/write-missing-destination.rs:5:5
+   |
+LL |     write!("S");
+   |     ^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+