youknowone · Jun 22, 2026 · Jun 15, 2026 · Jun 15, 2026 · Jun 15, 2026 · Jun 15, 2026
diff --git a/crates/stdlib/src/pystruct.rs b/crates/stdlib/src/pystruct.rs
@@ -51,9 +51,8 @@ pub(crate) mod _struct {
                     s
                 }
                 b @ PyBytes => {
-                    let ascii_str = ascii::AsciiStr::from_ascii(&b).map_err(|_| {
-                        new_struct_error(vm, "bad char in struct format".to_owned())
-                    })?;
+                    let ascii_str = ascii::AsciiStr::from_ascii(&b)
+                        .map_err(|_| new_struct_error(vm, "bad char in struct format"))?;
                     vm.ctx.new_str(ascii_str)
                 }
                 other =>
@@ -192,7 +191,7 @@ pub(crate) mod _struct {
             if format_spec.size == 0 {
                 Err(new_struct_error(
                     vm,
-                    "cannot iteratively unpack with a struct of length 0".to_owned(),
+                    "cannot iteratively unpack with a struct of length 0",
                 ))
             } else if !buffer.len().is_multiple_of(format_spec.size) {
                 Err(new_struct_error(

diff --git a/crates/vm/src/anystr.rs b/crates/vm/src/anystr.rs
@@ -1,15 +1,16 @@
+use core::ops::Range;
+
+use icu_properties::props::{
+    BinaryProperty, EnumeratedProperty, GeneralCategory, GeneralCategoryGroup,
+};
+use num_traits::{cast::ToPrimitive, sign::Signed};
+
 use crate::{
     Py, PyObject, PyObjectRef, PyResult, TryFromObject, VirtualMachine,
     builtins::{PyIntRef, PyTuple},
     convert::TryFromBorrowedObject,
     function::OptionalOption,
 };
-use icu_properties::props::{
-    BinaryProperty, EnumeratedProperty, GeneralCategory, GeneralCategoryGroup,
-};
-use num_traits::{cast::ToPrimitive, sign::Signed};
-
-use core::ops::Range;
 
 #[derive(FromArgs)]
 pub struct SplitArgs<T: TryFromObject> {
@@ -410,36 +411,20 @@ pub(crate) trait AnyStr {
 
     // _Py_bytes_islower
     fn py_islower(&self) -> bool {
-        let mut lower = false;
-        for byte in self
-            .as_bytes()
+        self.as_bytes()
             .iter()
             .copied()
             .filter(u8::is_ascii_alphabetic)
-        {
-            if byte.is_ascii_uppercase() {
-                return false;
-            }
-            lower = true;
-        }
-        lower
+            .all(|byte| byte.is_ascii_lowercase())
     }
 
     // Py_bytes_isupper
     fn py_isupper(&self) -> bool {
-        let mut upper = false;
-        for byte in self
-            .as_bytes()
+        self.as_bytes()
             .iter()
             .copied()
             .filter(u8::is_ascii_alphabetic)
-        {
-            if byte.is_ascii_lowercase() {
-                return false;
-            }
-            upper = true;
-        }
-        upper
+            .all(|byte| byte.is_ascii_uppercase())
     }
 
     // Unified form of CPython functions:
@@ -484,18 +469,17 @@ where
     F: Fn(T) -> PyResult<bool>,
     M: Fn(&PyObject) -> String,
 {
-    match obj.try_to_value::<T>(vm) {
-        Ok(single) => (predicate)(single),
-        Err(_) => {
-            let tuple: &Py<PyTuple> = obj
-                .try_to_value(vm)
-                .map_err(|_| vm.new_type_error((message)(obj)))?;
-            for obj in tuple {
-                if single_or_tuple_any(obj, predicate, message, vm)? {
-                    return Ok(true);
-                }
+    if let Ok(single) = obj.try_to_value::<T>(vm) {
+        (predicate)(single)
+    } else {
+        let tuple: &Py<PyTuple> = obj
+            .try_to_value(vm)
+            .map_err(|_| vm.new_type_error((message)(obj)))?;
+        for obj in tuple {
+            if single_or_tuple_any(obj, predicate, message, vm)? {
+                return Ok(true);
             }
-            Ok(false)
         }
+        Ok(false)
     }
 }
diff --git a/crates/vm/src/buffer.rs b/crates/vm/src/buffer.rs
@@ -5,8 +5,10 @@ use crate::{
     convert::ToPyObject,
     function::{ArgBytesLike, ArgIntoBool, ArgIntoFloat},
 };
-use alloc::fmt;
-use core::{iter::Peekable, mem};
+
+use rustpython_common::wtf8::Wtf8Buf;
+
+use core::{fmt, iter::Peekable, mem};
 use half::f16;
 use itertools::Itertools;
 use malachite_bigint::BigInt;
@@ -737,9 +739,8 @@ pub fn struct_error_type(vm: &VirtualMachine) -> &'static PyTypeRef {
     INSTANCE.get_or_init(|| vm.ctx.new_exception_type("struct", "error", None))
 }
 
-pub fn new_struct_error(vm: &VirtualMachine, msg: impl Into<String>) -> PyBaseExceptionRef {
+pub fn new_struct_error<T: Into<Wtf8Buf>>(vm: &VirtualMachine, msg: T) -> PyBaseExceptionRef {
     // can't just STRUCT_ERROR.get().unwrap() cause this could be called before from buffer
     // machinery, independent of whether _struct was ever imported
-    let msg: String = msg.into();
     vm.new_exception_msg(struct_error_type(vm).clone(), msg.into())
 }
diff --git a/crates/vm/src/builtins/float.rs b/crates/vm/src/builtins/float.rs
@@ -84,6 +84,7 @@ impl ToPyObject for f64 {
         vm.ctx.new_float(self).into()
     }
 }
+
 impl ToPyObject for f32 {
     fn to_pyobject(self, vm: &VirtualMachine) -> PyObjectRef {
         vm.ctx.new_float(f64::from(self)).into()
@@ -156,8 +157,7 @@ fn inner_divmod(v1: f64, v2: f64, vm: &VirtualMachine) -> PyResult<(f64, f64)> {
 
 pub(crate) fn float_pow(v1: f64, v2: f64, vm: &VirtualMachine) -> PyResult {
     if v1.is_zero() && v2.is_sign_negative() {
-        let msg = "zero to a negative power";
-        Err(vm.new_zero_division_error(msg.to_owned()))
+        Err(vm.new_zero_division_error("zero to a negative power"))
     } else if v1.is_sign_negative() && (v2.floor() - v2).abs() > f64::EPSILON {
         let v1 = Complex64::new(v1, 0.);
         let v2 = Complex64::new(v2, 0.);

diff --git a/crates/vm/src/builtins/staticmethod.rs b/crates/vm/src/builtins/staticmethod.rs
@@ -68,6 +68,7 @@ impl PyStaticMethod {
             callable: PyMutex::new(callable),
         }
     }
+
     #[deprecated(note = "use PyStaticMethod::new(...).into_ref() instead")]
     pub fn new_ref(callable: PyObjectRef, ctx: &Context) -> PyRef<Self> {
         Self::new(callable).into_ref(ctx)

diff --git a/crates/vm/src/byte.rs b/crates/vm/src/byte.rs
@@ -1,8 +1,9 @@
 //! byte operation APIs
-use crate::object::AsObject;
-use crate::{PyObject, PyResult, VirtualMachine};
+
 use num_traits::ToPrimitive;
 
+use crate::{AsObject, PyObject, PyResult, VirtualMachine};
+
 pub fn bytes_from_object(vm: &VirtualMachine, obj: &PyObject) -> PyResult<Vec<u8>> {
     if let Ok(elements) = obj.try_bytes_like(vm, |bytes| bytes.to_vec()) {
         return Ok(elements);