git.delta.rocks / jrsonnet / refs/commits / 3c2d9ee98ad3

difftreelog

feat thread_enter/thread_exit bindins

Yaroslav Bolyukin2024-05-28parent: #9070b9a.patch.diff
in: master

5 files changed

modifiedCargo.tomldiffbeforeafterboth
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -19,9 +19,7 @@
 jrsonnet-stdlib = { path = "./crates/jrsonnet-stdlib", version = "0.5.0-pre96" }
 jrsonnet-cli = { path = "./crates/jrsonnet-cli", version = "0.5.0-pre96" }
 jrsonnet-types = { path = "./crates/jrsonnet-types", version = "0.5.0-pre96" }
-
-jrsonnet-gcmodule = "0.3.6"
-
+jrsonnet-gcmodule = { version = "0.3.7" }
 # Diagnostics.
 # hi-doc is my library, which handles text formatting very well, but isn't polished enough yet
 # Previous implementation was based on annotate-snippets, which I don't like for many reasons.
modifiedbindings/c/libjsonnet.hdiffbeforeafterboth
--- a/bindings/c/libjsonnet.h
+++ b/bindings/c/libjsonnet.h
@@ -1,22 +1,9 @@
-/*
-Copyright 2015 Google Inc. All rights reserved.
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-    http://www.apache.org/licenses/LICENSE-2.0
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
 #ifndef LIB_JSONNET_H
 #define LIB_JSONNET_H
 
 #include <stddef.h>
 
-/** \file This file is a library interface for evaluating Jsonnet.  It is written in C++ but exposes
+/** \file This file is a library interface for evaluating Jsonnet. It is written in Rust but exposes
  * a C interface for easier wrapping by other languages.  See \see jsonnet_lib_test.c for an example
  * of using the library.
  */
@@ -28,10 +15,10 @@
  *
  * If this isn't the sae as jsonnet_version() then you've got a mismatched binary / header.
  */
-#define LIB_JSONNET_VERSION "v0.16.0"
+#define LIB_JSONNET_VERSION "v0.20.0"
 
 /** Return the version string of the Jsonnet interpreter.  Conforms to semantic versioning
- * http://semver.org/ If this does not match LIB_JSONNET_VERSION then there is a mismatch between
+ * https://semver.org/ If this does not match LIB_JSONNET_VERSION then there is a mismatch between
  * header and compiled library.
  */
 const char *jsonnet_version(void);
@@ -66,10 +53,12 @@
  *     process's CWD.  This is necessary so that imports from the content of the imported file can
  *     be resolved correctly.  Allocate memory with jsonnet_realloc.  Only use when *success = 1.
  * \param success Set this byref param to 1 to indicate success and 0 for failure.
- * \returns The content of the imported file, or an error message.
+ * \param buf Set this byref param to the content of the imported file, or an error message.  Allocate memory with jsonnet_realloc.  Do not include a null terminator byte.
+ * \param buflen Set this byref param to the length of the data returned in buf.
+ * \returns 0 to indicate success and 1 for failure.  On success, the content is in *buf.  On failure, an error message is in *buf.
  */
-typedef char *JsonnetImportCallback(void *ctx, const char *base, const char *rel, char **found_here,
-									int *success);
+typedef int JsonnetImportCallback(void *ctx, const char *base, const char *rel,
+                                  char **found_here, char **buf, size_t *buflen);
 
 /** An opaque type which can only be utilized via the jsonnet_json_* family of functions.
  */
@@ -82,7 +71,7 @@
 /** If the value is a number, return 1 and store the number in out, otherwise return 0.
  */
 int jsonnet_json_extract_number(struct JsonnetVm *vm, const struct JsonnetJsonValue *v,
-								double *out);
+                                double *out);
 
 /** Return 0 if the value is false, 1 if it is true, and 2 if it is not a bool.
  */
@@ -117,7 +106,7 @@
 /** Add v to the end of the array.
  */
 void jsonnet_json_array_append(struct JsonnetVm *vm, struct JsonnetJsonValue *arr,
-							   struct JsonnetJsonValue *v);
+                               struct JsonnetJsonValue *v);
 
 /** Make a JsonnetJsonValue representing an object with the given number of fields.
  *
@@ -130,7 +119,7 @@
  * This replaces any previous binding of the field.
  */
 void jsonnet_json_object_append(struct JsonnetVm *vm, struct JsonnetJsonValue *obj, const char *f,
-								struct JsonnetJsonValue *v);
+                                struct JsonnetJsonValue *v);
 
 /** Clean up a JSON subtree.
  *
@@ -151,8 +140,8 @@
  * \returns The content of the imported file, or an error message.
  */
 typedef struct JsonnetJsonValue *JsonnetNativeCallback(void *ctx,
-													   const struct JsonnetJsonValue *const *argv,
-													   int *success);
+                                                       const struct JsonnetJsonValue *const *argv,
+                                                       int *success);
 
 /** Allocate, resize, or free a buffer.  This will abort if the memory cannot be allocated.  It will
  * only return NULL if sz was zero.
@@ -181,7 +170,7 @@
  * \param params NULL-terminated array of the names of the params.  Must be valid identifiers.
  */
 void jsonnet_native_callback(struct JsonnetVm *vm, const char *name, JsonnetNativeCallback *cb,
-							 void *ctx, const char *const *params);
+                             void *ctx, const char *const *params);
 
 /** Bind a Jsonnet external var to the given string.
  *
@@ -236,7 +225,7 @@
  * \returns Either JSON or the error message.
  */
 char *jsonnet_evaluate_snippet(struct JsonnetVm *vm, const char *filename, const char *snippet,
-							   int *error);
+                               int *error);
 
 /** Evaluate a file containing Jsonnet code, return a number of named JSON files.
  *
@@ -260,7 +249,7 @@
  * \returns Either the error, or a sequence of strings separated by \0, terminated with \0\0.
  */
 char *jsonnet_evaluate_snippet_multi(struct JsonnetVm *vm, const char *filename,
-									 const char *snippet, int *error);
+                                     const char *snippet, int *error);
 
 /** Evaluate a file containing Jsonnet code, return a number of JSON files.
  *
@@ -284,9 +273,46 @@
  * \returns Either the error, or a sequence of strings separated by \0, terminated with \0\0.
  */
 char *jsonnet_evaluate_snippet_stream(struct JsonnetVm *vm, const char *filename,
-									  const char *snippet, int *error);
+                                      const char *snippet, int *error);
 
 /** Complement of \see jsonnet_vm_make. */
 void jsonnet_destroy(struct JsonnetVm *vm);
 
-#endif // LIB_JSONNET_H
+/** Jrsonnet addition.
+ *
+ * In jrsonnet, vm state is bound to the thread, because interpreter
+ * also uses thread_local storage for some things (I.e GC).
+ *
+ * It makes it impossible to correctly use those bindings in golang,
+ * where developer has little control over goroutine scheduler.
+ *
+ * To make it work, jrsonnet provides methods to dump and restore thread
+ * state manually, making it possible to wire it with golang.
+ */
+struct JrThreadCTX;
+
+/** Dump current thread state, to be restored with
+ * jrsonnet_reenter_thread.
+ */
+struct JrThreadCTX *jrsonnet_exit_thread();
+/** Restore thread state, freeing JrThreadCTX.
+ */
+void jrsonnet_reenter_thread(struct JrThreadCTX *ctx);
+
+struct JrThreadId;
+
+/** Get current thread id (opaque pointer).
+ */
+struct JrThreadId* jrsonnet_thread_id();
+
+/** Compare two thread ids, it is not the same as a == b.
+ *
+ * \returns 1 if the same thread, 0 otherwise
+ */
+int jrsonnet_thread_id_compare(struct JrThreadId *a, struct JrThreadId *b);
+
+/** Free thread id value.
+ */
+void jrsonnet_thread_id_free(struct JrThreadId *id);
+
+#endif  // LIB_JSONNET_H
modifiedbindings/jsonnet/Cargo.tomldiffbeforeafterboth
--- a/bindings/jsonnet/Cargo.toml
+++ b/bindings/jsonnet/Cargo.toml
@@ -23,6 +23,7 @@
 jrsonnet-parser.workspace = true
 jrsonnet-stdlib.workspace = true
 jrsonnet-gcmodule.workspace = true
+jrsonnet-interner.workspace = true
 
 [lib]
 name = "jsonnet"
modifiedbindings/jsonnet/src/lib.rsdiffbeforeafterboth
--- a/bindings/jsonnet/src/lib.rs
+++ b/bindings/jsonnet/src/lib.rs
@@ -40,7 +40,7 @@
 /// then there is a mismatch between header and compiled library.
 #[no_mangle]
 pub extern "C" fn jsonnet_version() -> &'static [u8; 8] {
-	b"v0.19.1\0"
+	b"v0.20.0\0"
 }
 
 unsafe fn parse_path(input: &CStr) -> Cow<Path> {
modifiedcrates/jrsonnet-interner/src/lib.rsdiffbeforeafterboth
before · crates/jrsonnet-interner/src/lib.rs
1#![deny(2	unsafe_op_in_unsafe_fn,3	clippy::missing_safety_doc,4	clippy::undocumented_unsafe_blocks5)]6#![warn(clippy::pedantic, clippy::nursery)]7#![allow(clippy::missing_const_for_fn)]8use std::{9	borrow::Cow,10	cell::RefCell,11	fmt::{self, Display},12	hash::{BuildHasherDefault, Hash, Hasher},13	ops::Deref,14	str,15};1617use hashbrown::{hash_map::RawEntryMut, HashMap};18use jrsonnet_gcmodule::Trace;19use rustc_hash::FxHasher;2021mod inner;22use inner::Inner;2324/// Interned string25///26/// Provides O(1) comparsions and hashing, cheap copy, and cheap conversion to [`IBytes`]27#[derive(Clone, PartialOrd, Ord, Eq)]28pub struct IStr(Inner);29impl Trace for IStr {30	fn is_type_tracked() -> bool {31		false32	}33}3435impl IStr {36	#[must_use]37	pub fn empty() -> Self {38		"".into()39	}40	#[must_use]41	pub fn as_str(&self) -> &str {42		self as &str43	}4445	#[must_use]46	pub fn cast_bytes(self) -> IBytes {47		IBytes(self.0.clone())48	}49}5051impl Deref for IStr {52	type Target = str;5354	fn deref(&self) -> &Self::Target {55		// SAFETY: Inner::check_utf8 is called on IStr construction, data is utf-856		unsafe { self.0.as_str_unchecked() }57	}58}5960impl PartialEq for IStr {61	fn eq(&self, other: &Self) -> bool {62		// all IStr should be inlined into same pool63		Inner::ptr_eq(&self.0, &other.0)64	}65}6667impl PartialEq<str> for IStr {68	fn eq(&self, other: &str) -> bool {69		self as &str == other70	}71}7273impl Hash for IStr {74	fn hash<H: Hasher>(&self, state: &mut H) {75		// IStr is always obtained from pool, where no string have duplicate, thus every unique string has unique address76		state.write_usize(Inner::as_ptr(&self.0).cast::<()>() as usize);77	}78}7980impl Drop for IStr {81	fn drop(&mut self) {82		maybe_unpool(&self.0);83	}84}8586impl fmt::Debug for IStr {87	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {88		fmt::Debug::fmt(self as &str, f)89	}90}9192impl Display for IStr {93	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {94		fmt::Display::fmt(self as &str, f)95	}96}9798/// Interned byte array99#[derive(Clone, PartialOrd, Ord, Eq)]100pub struct IBytes(Inner);101impl Trace for IBytes {102	fn is_type_tracked() -> bool {103		false104	}105}106107impl IBytes {108	#[must_use]109	pub fn cast_str(self) -> Option<IStr> {110		if Inner::check_utf8(&self.0) {111			Some(IStr(self.0.clone()))112		} else {113			None114		}115	}116	/// # Safety117	/// data should be valid utf8118	unsafe fn cast_str_unchecked(self) -> IStr {119		// SAFETY: data is utf8120		unsafe { Inner::assume_utf8(&self.0) };121		IStr(self.0.clone())122	}123124	#[must_use]125	pub fn as_slice(&self) -> &[u8] {126		self.0.as_slice()127	}128}129130impl Deref for IBytes {131	type Target = [u8];132133	fn deref(&self) -> &Self::Target {134		self.0.as_slice()135	}136}137138impl PartialEq for IBytes {139	fn eq(&self, other: &Self) -> bool {140		// all IStr should be inlined into same pool141		Inner::ptr_eq(&self.0, &other.0)142	}143}144145impl Hash for IBytes {146	fn hash<H: Hasher>(&self, state: &mut H) {147		// IBytes is always obtained from pool, where no string have duplicate, thus every unique string has unique address148		state.write_usize(Inner::as_ptr(&self.0).cast::<()>() as usize);149	}150}151152impl Drop for IBytes {153	fn drop(&mut self) {154		maybe_unpool(&self.0);155	}156}157158fn maybe_unpool(inner: &Inner) {159	#[cold]160	#[inline(never)]161	fn unpool(inner: &Inner) {162		// May fail on program termination163		let _ = POOL.try_with(|pool| {164			let mut pool = pool.borrow_mut();165166			if pool.remove(inner).is_none() {167				// On some platforms (i.e i686-windows), try_with will not fail after TLS168				// destructor is called, but instead re-initialize the TLS with the empty pool.169				// Allow non-pooled Drop in this case.170				// https://github.com/CertainLach/jrsonnet/issues/98#issuecomment-1591624016171				//172				// However, if pool is not empty, most likely this is issue #113, and then I don't173				// have any explainations for now.174				assert!(pool.is_empty(), "received an unpooled string not during the program termination, please write any info regarding this crash to https://github.com/CertainLach/jrsonnet/issues/113, thanks!");175			}176		});177	}178	// First reference - current object, second - POOL179	if Inner::strong_count(inner) <= 2 {180		unpool(inner);181	}182}183184impl fmt::Debug for IBytes {185	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {186		fmt::Debug::fmt(self as &[u8], f)187	}188}189190impl<'c> From<Cow<'c, str>> for IStr {191	fn from(v: Cow<'c, str>) -> Self {192		intern_str(&v)193	}194}195impl From<&str> for IStr {196	fn from(v: &str) -> Self {197		intern_str(v)198	}199}200impl From<String> for IStr {201	fn from(s: String) -> Self {202		s.as_str().into()203	}204}205impl From<&String> for IStr {206	fn from(s: &String) -> Self {207		s.as_str().into()208	}209}210impl From<char> for IStr {211	fn from(value: char) -> Self {212		let mut buf = [0; 5];213		Self::from(&*value.encode_utf8(&mut buf))214	}215}216impl From<&[u8]> for IBytes {217	fn from(v: &[u8]) -> Self {218		intern_bytes(v)219	}220}221222thread_local! {223	static POOL: RefCell<HashMap<Inner, (), BuildHasherDefault<FxHasher>>> = RefCell::new(HashMap::with_capacity_and_hasher(200, BuildHasherDefault::default()));224}225226#[must_use]227pub fn intern_bytes(bytes: &[u8]) -> IBytes {228	POOL.with(|pool| {229		let mut pool = pool.borrow_mut();230		let entry = pool.raw_entry_mut().from_key(bytes);231		match entry {232			RawEntryMut::Occupied(i) => IBytes(i.get_key_value().0.clone()),233			RawEntryMut::Vacant(e) => {234				let (k, ()) = e.insert(Inner::new_bytes(bytes), ());235				IBytes(k.clone())236			}237		}238	})239}240241#[must_use]242pub fn intern_str(str: &str) -> IStr {243	// SAFETY: Rust strings always utf8244	unsafe { intern_bytes(str.as_bytes()).cast_str_unchecked() }245}246247#[cfg(test)]248mod tests {249	use crate::IStr;250251	#[test]252	fn simple() {253		let a = IStr::from("a");254		let b = IStr::from("a");255256		assert_eq!(a.as_ptr(), b.as_ptr());257	}258}
after · crates/jrsonnet-interner/src/lib.rs
1#![deny(2	unsafe_op_in_unsafe_fn,3	clippy::missing_safety_doc,4	clippy::undocumented_unsafe_blocks5)]6#![warn(clippy::pedantic, clippy::nursery)]7#![allow(clippy::missing_const_for_fn)]8use std::{9	borrow::Cow,10	cell::RefCell,11	fmt::{self, Display},12	hash::{BuildHasherDefault, Hash, Hasher},13	ops::Deref,14	str,15};1617use hashbrown::{hash_map::RawEntryMut, HashMap};18use jrsonnet_gcmodule::Trace;19use rustc_hash::FxHasher;2021mod inner;22use inner::Inner;2324/// Interned string25///26/// Provides O(1) comparsions and hashing, cheap copy, and cheap conversion to [`IBytes`]27#[derive(Clone, PartialOrd, Ord, Eq)]28pub struct IStr(Inner);29impl Trace for IStr {30	fn is_type_tracked() -> bool {31		false32	}33}3435impl IStr {36	#[must_use]37	pub fn empty() -> Self {38		"".into()39	}40	#[must_use]41	pub fn as_str(&self) -> &str {42		self as &str43	}4445	#[must_use]46	pub fn cast_bytes(self) -> IBytes {47		IBytes(self.0.clone())48	}49}5051impl Deref for IStr {52	type Target = str;5354	fn deref(&self) -> &Self::Target {55		// SAFETY: Inner::check_utf8 is called on IStr construction, data is utf-856		unsafe { self.0.as_str_unchecked() }57	}58}5960impl PartialEq for IStr {61	fn eq(&self, other: &Self) -> bool {62		// all IStr should be inlined into same pool63		Inner::ptr_eq(&self.0, &other.0)64	}65}6667impl PartialEq<str> for IStr {68	fn eq(&self, other: &str) -> bool {69		self as &str == other70	}71}7273impl Hash for IStr {74	fn hash<H: Hasher>(&self, state: &mut H) {75		// IStr is always obtained from pool, where no string have duplicate, thus every unique string has unique address76		state.write_usize(Inner::as_ptr(&self.0).cast::<()>() as usize);77	}78}7980impl Drop for IStr {81	fn drop(&mut self) {82		maybe_unpool(&self.0);83	}84}8586impl fmt::Debug for IStr {87	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {88		fmt::Debug::fmt(self as &str, f)89	}90}9192impl Display for IStr {93	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {94		fmt::Display::fmt(self as &str, f)95	}96}9798/// Interned byte array99#[derive(Clone, PartialOrd, Ord, Eq)]100pub struct IBytes(Inner);101impl Trace for IBytes {102	fn is_type_tracked() -> bool {103		false104	}105}106107impl IBytes {108	#[must_use]109	pub fn cast_str(self) -> Option<IStr> {110		if Inner::check_utf8(&self.0) {111			Some(IStr(self.0.clone()))112		} else {113			None114		}115	}116	/// # Safety117	/// data should be valid utf8118	unsafe fn cast_str_unchecked(self) -> IStr {119		// SAFETY: data is utf8120		unsafe { Inner::assume_utf8(&self.0) };121		IStr(self.0.clone())122	}123124	#[must_use]125	pub fn as_slice(&self) -> &[u8] {126		self.0.as_slice()127	}128}129130impl Deref for IBytes {131	type Target = [u8];132133	fn deref(&self) -> &Self::Target {134		self.0.as_slice()135	}136}137138impl PartialEq for IBytes {139	fn eq(&self, other: &Self) -> bool {140		// all IStr should be inlined into same pool141		Inner::ptr_eq(&self.0, &other.0)142	}143}144145impl Hash for IBytes {146	fn hash<H: Hasher>(&self, state: &mut H) {147		// IBytes is always obtained from pool, where no string have duplicate, thus every unique string has unique address148		state.write_usize(Inner::as_ptr(&self.0).cast::<()>() as usize);149	}150}151152impl Drop for IBytes {153	fn drop(&mut self) {154		maybe_unpool(&self.0);155	}156}157158fn maybe_unpool(inner: &Inner) {159	#[cold]160	#[inline(never)]161	fn unpool(inner: &Inner) {162		// May fail on program termination163		let _ = POOL.try_with(|pool| {164			let mut pool = pool.borrow_mut();165166			if pool.remove(inner).is_none() {167				// On some platforms (i.e i686-windows), try_with will not fail after TLS168				// destructor is called, but instead re-initialize the TLS with the empty pool.169				// Allow non-pooled Drop in this case.170				// https://github.com/CertainLach/jrsonnet/issues/98#issuecomment-1591624016171				//172				// However, if pool is not empty, most likely this is issue #113, and then I don't173				// have any explainations for now.174				assert!(pool.is_empty(), "received an unpooled string not during the program termination, please write any info regarding this crash to https://github.com/CertainLach/jrsonnet/issues/113, thanks!");175			}176		});177	}178	// First reference - current object, second - POOL179	if Inner::strong_count(inner) <= 2 {180		unpool(inner);181	}182}183184impl fmt::Debug for IBytes {185	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {186		fmt::Debug::fmt(self as &[u8], f)187	}188}189190impl<'c> From<Cow<'c, str>> for IStr {191	fn from(v: Cow<'c, str>) -> Self {192		intern_str(&v)193	}194}195impl From<&str> for IStr {196	fn from(v: &str) -> Self {197		intern_str(v)198	}199}200impl From<String> for IStr {201	fn from(s: String) -> Self {202		s.as_str().into()203	}204}205impl From<&String> for IStr {206	fn from(s: &String) -> Self {207		s.as_str().into()208	}209}210impl From<char> for IStr {211	fn from(value: char) -> Self {212		let mut buf = [0; 5];213		Self::from(&*value.encode_utf8(&mut buf))214	}215}216impl From<&[u8]> for IBytes {217	fn from(v: &[u8]) -> Self {218		intern_bytes(v)219	}220}221222type PoolMap = HashMap<Inner, (), BuildHasherDefault<FxHasher>>;223224thread_local! {225	static POOL: RefCell<PoolMap> = RefCell::new(HashMap::with_capacity_and_hasher(200, BuildHasherDefault::default()));226}227228/// Jrsonnet golang bindings require that it is possible to move jsonnet229/// VM between OS threads, and this is not possible due to usage of230/// `thread_local`. Instead, there is two methods added, one should be231/// called at the end of current thread work, and one that should be232/// used when using other thread.233pub mod interop {234	use std::mem;235236	use crate::{PoolMap, POOL};237238	pub enum PoolState {}239240	/// Dump current interned string pool, to be restored by241	/// `reenter_thread`242	pub fn exit_thread() -> *mut PoolState {243		Box::into_raw(Box::new(POOL.with_borrow_mut(mem::take))).cast()244	}245246	/// Reenter thread, using state dumped by `exit_thread`.247	///248	/// # Safety249	///250	/// `state` should be acquired from `exit_thread`, it is not allowed251	/// to reuse state to reenter multiple threads.252	pub unsafe fn reenter_thread(state: *mut PoolState) {253		let ptr: *mut PoolMap = state.cast();254		// SAFETY: ptr is an unique state per method safety requirements.255		let ptr: Box<PoolMap> = unsafe { Box::from_raw(ptr) };256		let ptr: PoolMap = *ptr;257		POOL.with_borrow_mut(|pool| {258			let _ = mem::replace(pool, ptr);259		});260	}261}262263#[must_use]264pub fn intern_bytes(bytes: &[u8]) -> IBytes {265	POOL.with(|pool| {266		let mut pool = pool.borrow_mut();267		let entry = pool.raw_entry_mut().from_key(bytes);268		match entry {269			RawEntryMut::Occupied(i) => IBytes(i.get_key_value().0.clone()),270			RawEntryMut::Vacant(e) => {271				let (k, ()) = e.insert(Inner::new_bytes(bytes), ());272				IBytes(k.clone())273			}274		}275	})276}277278#[must_use]279pub fn intern_str(str: &str) -> IStr {280	// SAFETY: Rust strings always utf8281	unsafe { intern_bytes(str.as_bytes()).cast_str_unchecked() }282}283284#[cfg(test)]285mod tests {286	use crate::IStr;287288	#[test]289	fn simple() {290		let a = IStr::from("a");291		let b = IStr::from("a");292293		assert_eq!(a.as_ptr(), b.as_ptr());294	}295}