smartstring/lib.rs
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// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
//! # Smart String
//!
//! [`SmartString`] is a wrapper around [`String`] which offers
//! automatic inlining of small strings. It comes in two flavours:
//! [`LazyCompact`], which takes up exactly as much space as a [`String`]
//! and is generally a little faster, and [`Compact`], which is the same as
//! [`LazyCompact`] except it will aggressively re-inline any expanded
//! [`String`]s which become short enough to do so.
//! [`LazyCompact`] is the default, and what you should be using unless
//! you care considerably more about heap memory usage than performance.
//!
//! ## What Is It For?
//!
//! The intended use for [`SmartString`] is as a key type for a
//! B-tree (such as [`std::collections::BTreeMap`]) or any kind of
//! array operation where cache locality is critical.
//!
//! In general, it's a nice data type for reducing your heap allocations and
//! increasing the locality of string data. If you use [`SmartString`]
//! as a drop-in replacement for [`String`], you're almost certain to see
//! a slight performance boost, as well as slightly reduced memory usage.
//!
//! ## How To Use It?
//!
//! [`SmartString`] has the exact same API as [`String`],
//! all the clever bits happen automatically behind the scenes, so you could just:
//!
//! ```rust
//! use smartstring::alias::String;
//! use std::fmt::Write;
//!
//! let mut string = String::new();
//! string.push_str("This is just a string!");
//! string.clear();
//! write!(string, "Hello Joe!");
//! assert_eq!("Hello Joe!", string);
//! ```
//!
//! ## Give Me The Details
//!
//! [`SmartString`] is the same size as [`String`] and
//! relies on pointer alignment to be able to store a discriminant bit in its
//! inline form that will never be present in its [`String`] form, thus
//! giving us 24 bytes (on 64-bit architectures) minus one bit to encode our
//! inline string. It uses 23 bytes to store the string data and the remaining
//! 7 bits to encode the string's length. When the available space is exceeded,
//! it swaps itself out with a boxed string type containing its previous
//! contents. Likewise, if the string's length should drop below its inline
//! capacity again, it deallocates the string and moves its contents inline.
//!
//! In [`Compact`] mode, it is aggressive about inlining strings, meaning that if you modify a heap allocated
//! string such that it becomes short enough for inlining, it will be inlined immediately
//! and the allocated [`String`] will be dropped. This may cause multiple
//! unintended allocations if you repeatedly adjust your string's length across the
//! inline capacity threshold, so if your string's construction can get
//! complicated and you're relying on performance during construction, it might be better
//! to construct it as a [`String`] and convert it once construction is done.
//!
//! [`LazyCompact`] looks the same as [`Compact`], except
//! it never re-inlines a string that's already been heap allocated, instead
//! keeping the allocation around in case it needs it. This makes for less
//! cache local strings, but is the best choice if you're more worried about
//! time spent on unnecessary allocations than cache locality.
//!
//! ## Performance
//!
//! It doesn't aim to be more performant than [`String`] in the general case,
//! except that it doesn't trigger heap allocations for anything shorter than
//! its inline capacity and so can be reasonably expected to exceed
//! [`String`]'s performance perceptibly on shorter strings, as well as being more
//! memory efficient in these cases. There will always be a slight overhead on all
//! operations on boxed strings, compared to [`String`].
//!
//! ## Feature Flags
//!
//! `smartstring` comes with optional support for the following crates through Cargo
//! feature flags. You can enable them in your `Cargo.toml` file like this:
//!
//! ```no_compile
//! [dependencies]
//! smartstring = { version = "*", features = ["proptest", "serde"] }
//! ```
//!
//! | Feature | Description |
//! | ------- | ----------- |
//! | [`arbitrary`](https://crates.io/crates/arbitrary) | [`Arbitrary`][Arbitrary] implementation for [`SmartString`]. |
//! | [`proptest`](https://crates.io/crates/proptest) | A strategy for generating [`SmartString`]s from a regular expression. |
//! | [`serde`](https://crates.io/crates/serde) | [`Serialize`][Serialize] and [`Deserialize`][Deserialize] implementations for [`SmartString`]. |
//!
//! [Serialize]: https://docs.rs/serde/latest/serde/trait.Serialize.html
//! [Deserialize]: https://docs.rs/serde/latest/serde/trait.Deserialize.html
//! [Arbitrary]: https://docs.rs/arbitrary/latest/arbitrary/trait.Arbitrary.html
// Ensure all unsafe blocks get flagged for manual validation.
#![deny(unsafe_code)]
#![forbid(rust_2018_idioms)]
#![deny(nonstandard_style)]
#![warn(unreachable_pub, missing_debug_implementations, missing_docs)]
#![cfg_attr(not(feature = "std"), no_std)]
#![cfg_attr(needs_allocator_feature, feature(allocator_api))]
extern crate alloc;
use alloc::{
boxed::Box,
string::{String, ToString},
};
use core::{
borrow::{Borrow, BorrowMut},
cmp::Ordering,
convert::Infallible,
fmt::{Debug, Display, Error, Formatter, Write},
hash::{Hash, Hasher},
iter::FromIterator,
marker::PhantomData,
mem::{forget, MaybeUninit},
ops::{
Add, Deref, DerefMut, Index, IndexMut, Range, RangeBounds, RangeFrom, RangeFull,
RangeInclusive, RangeTo, RangeToInclusive,
},
ptr::drop_in_place,
str::FromStr,
};
#[cfg(feature = "std")]
use std::borrow::Cow;
mod config;
pub use config::{Compact, LazyCompact, SmartStringMode, MAX_INLINE};
mod marker_byte;
use marker_byte::Discriminant;
mod inline;
use inline::InlineString;
mod boxed;
use boxed::BoxedString;
mod casts;
use casts::{StringCast, StringCastInto, StringCastMut};
mod iter;
pub use iter::Drain;
mod ops;
use ops::{string_op_grow, string_op_shrink};
#[cfg(feature = "serde")]
mod serde;
#[cfg(feature = "arbitrary")]
mod arbitrary;
#[cfg(feature = "proptest")]
pub mod proptest;
/// Convenient type aliases.
pub mod alias {
use super::*;
/// A convenience alias for a [`LazyCompact`] layout [`SmartString`].
///
/// Just pretend it's a [`String`][String]!
pub type String = SmartString<LazyCompact>;
/// A convenience alias for a [`Compact`] layout [`SmartString`].
pub type CompactString = SmartString<Compact>;
}
/// A smart string.
///
/// This wraps one of two string types: an inline string or a boxed string.
/// Conversion between the two happens opportunistically and transparently.
///
/// It takes a layout as its type argument: one of [`Compact`] or [`LazyCompact`].
///
/// It mimics the interface of [`String`] except where behaviour cannot
/// be guaranteed to stay consistent between its boxed and inline states. This means
/// you still have `capacity()` and `shrink_to_fit()`, relating to state that only
/// really exists in the boxed variant, because the inline variant can still give
/// sensible behaviour for these operations, but `with_capacity()`, `reserve()` etc are
/// absent, because they would have no effect on inline strings and the requested
/// state changes wouldn't carry over if the inline string is promoted to a boxed
/// one - not without also storing that state in the inline representation, which
/// would waste precious bytes for inline string data.
pub struct SmartString<Mode: SmartStringMode> {
data: MaybeUninit<InlineString>,
mode: PhantomData<Mode>,
}
impl<Mode: SmartStringMode> Drop for SmartString<Mode> {
fn drop(&mut self) {
if let StringCastMut::Boxed(string) = self.cast_mut() {
#[allow(unsafe_code)]
unsafe {
drop_in_place(string)
};
}
}
}
impl<Mode: SmartStringMode> Clone for SmartString<Mode> {
/// Clone a [`SmartString`].
///
/// If the string is inlined, this is a [`Copy`] operation. Otherwise,
/// a string with the same capacity as the source is allocated.
fn clone(&self) -> Self {
match self.cast() {
StringCast::Boxed(string) => Self::from_boxed(string.clone()),
StringCast::Inline(string) => Self::from_inline(*string),
}
}
}
impl<Mode: SmartStringMode> Deref for SmartString<Mode> {
type Target = str;
#[inline(always)]
fn deref(&self) -> &Self::Target {
match self.cast() {
StringCast::Boxed(string) => string.deref(),
StringCast::Inline(string) => string.deref(),
}
}
}
impl<Mode: SmartStringMode> DerefMut for SmartString<Mode> {
#[inline(always)]
fn deref_mut(&mut self) -> &mut Self::Target {
match self.cast_mut() {
StringCastMut::Boxed(string) => string.deref_mut(),
StringCastMut::Inline(string) => string.deref_mut(),
}
}
}
impl SmartString<LazyCompact> {
/// Construct an empty string.
///
/// This is a `const fn` version of [`SmartString::new`].
/// It's a temporary measure while we wait for trait bounds on
/// type arguments to `const fn`s to stabilise, and will be deprecated
/// once this happens.
pub const fn new_const() -> Self {
Self {
data: MaybeUninit::new(InlineString::new()),
mode: PhantomData,
}
}
}
impl SmartString<Compact> {
/// Construct an empty string.
///
/// This is a `const fn` version of [`SmartString::new`].
/// It's a temporary measure while we wait for trait bounds on
/// type arguments to `const fn`s to stabilise, and will be deprecated
/// once this happens.
pub const fn new_const() -> Self {
Self {
data: MaybeUninit::new(InlineString::new()),
mode: PhantomData,
}
}
}
impl<Mode: SmartStringMode> SmartString<Mode> {
/// Construct an empty string.
#[inline(always)]
pub fn new() -> Self {
Self::from_inline(InlineString::new())
}
fn from_boxed(boxed: BoxedString) -> Self {
let mut out = Self {
data: MaybeUninit::uninit(),
mode: PhantomData,
};
let data_ptr: *mut BoxedString = out.data.as_mut_ptr().cast();
#[allow(unsafe_code)]
unsafe {
data_ptr.write(boxed)
};
out
}
fn from_inline(inline: InlineString) -> Self {
Self {
data: MaybeUninit::new(inline),
mode: PhantomData,
}
}
fn discriminant(&self) -> Discriminant {
// unsafe { self.data.assume_init() }.marker.discriminant()
let str_ptr: *const BoxedString =
self.data.as_ptr().cast() as *const _ as *const BoxedString;
#[allow(unsafe_code)]
Discriminant::from_bit(BoxedString::check_alignment(unsafe { &*str_ptr }))
}
fn cast(&self) -> StringCast<'_> {
#[allow(unsafe_code)]
match self.discriminant() {
Discriminant::Inline => StringCast::Inline(unsafe { &*self.data.as_ptr() }),
Discriminant::Boxed => StringCast::Boxed(unsafe { &*self.data.as_ptr().cast() }),
}
}
fn cast_mut(&mut self) -> StringCastMut<'_> {
#[allow(unsafe_code)]
match self.discriminant() {
Discriminant::Inline => StringCastMut::Inline(unsafe { &mut *self.data.as_mut_ptr() }),
Discriminant::Boxed => {
StringCastMut::Boxed(unsafe { &mut *self.data.as_mut_ptr().cast() })
}
}
}
fn cast_into(mut self) -> StringCastInto {
#[allow(unsafe_code)]
match self.discriminant() {
Discriminant::Inline => StringCastInto::Inline(unsafe { self.data.assume_init() }),
Discriminant::Boxed => StringCastInto::Boxed(unsafe {
let boxed_ptr: *mut BoxedString = self.data.as_mut_ptr().cast();
let string = boxed_ptr.read();
forget(self);
string
}),
}
}
fn promote_from(&mut self, string: BoxedString) {
debug_assert!(self.discriminant() == Discriminant::Inline);
let data: *mut BoxedString = self.data.as_mut_ptr().cast();
#[allow(unsafe_code)]
unsafe {
data.write(string)
};
}
/// Attempt to inline the string if it's currently heap allocated.
///
/// Returns the resulting state: `true` if it's inlined, `false` if it's not.
fn try_demote(&mut self) -> bool {
if Mode::DEALLOC {
self.really_try_demote()
} else {
false
}
}
/// Attempt to inline the string regardless of whether `Mode::DEALLOC` is set.
fn really_try_demote(&mut self) -> bool {
if let StringCastMut::Boxed(string) = self.cast_mut() {
if string.len() > MAX_INLINE {
false
} else {
let s: &str = string.deref();
let inlined = s.into();
#[allow(unsafe_code)]
unsafe {
drop_in_place(string);
self.data.as_mut_ptr().write(inlined);
}
true
}
} else {
true
}
}
/// Return the length in bytes of the string.
///
/// Note that this may differ from the length in `char`s.
pub fn len(&self) -> usize {
match self.cast() {
StringCast::Boxed(string) => string.len(),
StringCast::Inline(string) => string.len(),
}
}
/// Test whether the string is empty.
pub fn is_empty(&self) -> bool {
self.len() == 0
}
/// Test whether the string is currently inlined.
pub fn is_inline(&self) -> bool {
self.discriminant() == Discriminant::Inline
}
/// Get a reference to the string as a string slice.
pub fn as_str(&self) -> &str {
self.deref()
}
/// Get a reference to the string as a mutable string slice.
pub fn as_mut_str(&mut self) -> &mut str {
self.deref_mut()
}
/// Return the currently allocated capacity of the string.
///
/// Note that if this is a boxed string, it returns [`String::capacity()`][String::capacity],
/// but an inline string always returns [`MAX_INLINE`].
///
/// Note also that if a boxed string is converted into an inline string, its capacity is
/// deallocated, and if the inline string is promoted to a boxed string in the future,
/// it will be reallocated with a default capacity.
pub fn capacity(&self) -> usize {
if let StringCast::Boxed(string) = self.cast() {
string.capacity()
} else {
MAX_INLINE
}
}
/// Push a character to the end of the string.
pub fn push(&mut self, ch: char) {
string_op_grow!(ops::Push, self, ch)
}
/// Copy a string slice onto the end of the string.
pub fn push_str(&mut self, string: &str) {
string_op_grow!(ops::PushStr, self, string)
}
/// Shrink the capacity of the string to fit its contents exactly.
///
/// This has no effect on inline strings, which always have a fixed capacity.
/// Thus, it's not safe to assume that [`capacity()`][SmartString::capacity] will
/// equal [`len()`][SmartString::len] after calling this.
///
/// Calling this on a [`LazyCompact`] string that is currently
/// heap allocated but is short enough to be inlined will deallocate the
/// heap allocation and convert it to an inline string.
pub fn shrink_to_fit(&mut self) {
if let StringCastMut::Boxed(string) = self.cast_mut() {
if string.len() > MAX_INLINE {
string.shrink_to_fit();
}
}
self.really_try_demote();
}
/// Truncate the string to `new_len` bytes.
///
/// If `new_len` is larger than the string's current length, this does nothing.
/// If `new_len` isn't on a UTF-8 character boundary, this method panics.
pub fn truncate(&mut self, new_len: usize) {
string_op_shrink!(ops::Truncate, self, new_len)
}
/// Pop a `char` off the end of the string.
pub fn pop(&mut self) -> Option<char> {
string_op_shrink!(ops::Pop, self)
}
/// Remove a `char` from the string at the given index.
///
/// If the index doesn't fall on a UTF-8 character boundary, this method panics.
pub fn remove(&mut self, index: usize) -> char {
string_op_shrink!(ops::Remove, self, index)
}
/// Insert a `char` into the string at the given index.
///
/// If the index doesn't fall on a UTF-8 character boundary, this method panics.
pub fn insert(&mut self, index: usize, ch: char) {
string_op_grow!(ops::Insert, self, index, ch)
}
/// Insert a string slice into the string at the given index.
///
/// If the index doesn't fall on a UTF-8 character boundary, this method panics.
pub fn insert_str(&mut self, index: usize, string: &str) {
string_op_grow!(ops::InsertStr, self, index, string)
}
/// Split the string into two at the given index.
///
/// Returns the content to the right of the index as a new string, and removes
/// it from the original.
///
/// If the index doesn't fall on a UTF-8 character boundary, this method panics.
pub fn split_off(&mut self, index: usize) -> Self {
string_op_shrink!(ops::SplitOff<Mode>, self, index)
}
/// Clear the string.
///
/// This causes any memory reserved by the string to be immediately deallocated.
pub fn clear(&mut self) {
*self = Self::new();
}
/// Filter out `char`s not matching a predicate.
pub fn retain<F>(&mut self, f: F)
where
F: FnMut(char) -> bool,
{
string_op_shrink!(ops::Retain, self, f)
}
/// Construct a draining iterator over a given range.
///
/// This removes the given range from the string, and returns an iterator over the
/// removed `char`s.
pub fn drain<R>(&mut self, range: R) -> Drain<'_, Mode>
where
R: RangeBounds<usize>,
{
Drain::new(self, range)
}
/// Replaces a range with the contents of a string slice.
pub fn replace_range<R>(&mut self, range: R, replace_with: &str)
where
R: RangeBounds<usize>,
{
string_op_grow!(ops::ReplaceRange, self, &range, replace_with);
self.try_demote();
}
}
impl<Mode: SmartStringMode> Default for SmartString<Mode> {
fn default() -> Self {
Self::new()
}
}
impl<Mode: SmartStringMode> AsRef<str> for SmartString<Mode> {
fn as_ref(&self) -> &str {
self.deref()
}
}
impl<Mode: SmartStringMode> AsMut<str> for SmartString<Mode> {
fn as_mut(&mut self) -> &mut str {
self.deref_mut()
}
}
impl<Mode: SmartStringMode> AsRef<[u8]> for SmartString<Mode> {
fn as_ref(&self) -> &[u8] {
self.deref().as_bytes()
}
}
impl<Mode: SmartStringMode> Borrow<str> for SmartString<Mode> {
fn borrow(&self) -> &str {
self.deref()
}
}
impl<Mode: SmartStringMode> BorrowMut<str> for SmartString<Mode> {
fn borrow_mut(&mut self) -> &mut str {
self.deref_mut()
}
}
impl<Mode: SmartStringMode> Index<Range<usize>> for SmartString<Mode> {
type Output = str;
fn index(&self, index: Range<usize>) -> &Self::Output {
&self.deref()[index]
}
}
impl<Mode: SmartStringMode> Index<RangeTo<usize>> for SmartString<Mode> {
type Output = str;
fn index(&self, index: RangeTo<usize>) -> &Self::Output {
&self.deref()[index]
}
}
impl<Mode: SmartStringMode> Index<RangeFrom<usize>> for SmartString<Mode> {
type Output = str;
fn index(&self, index: RangeFrom<usize>) -> &Self::Output {
&self.deref()[index]
}
}
impl<Mode: SmartStringMode> Index<RangeFull> for SmartString<Mode> {
type Output = str;
fn index(&self, _index: RangeFull) -> &Self::Output {
self.deref()
}
}
impl<Mode: SmartStringMode> Index<RangeInclusive<usize>> for SmartString<Mode> {
type Output = str;
fn index(&self, index: RangeInclusive<usize>) -> &Self::Output {
&self.deref()[index]
}
}
impl<Mode: SmartStringMode> Index<RangeToInclusive<usize>> for SmartString<Mode> {
type Output = str;
fn index(&self, index: RangeToInclusive<usize>) -> &Self::Output {
&self.deref()[index]
}
}
impl<Mode: SmartStringMode> IndexMut<Range<usize>> for SmartString<Mode> {
fn index_mut(&mut self, index: Range<usize>) -> &mut Self::Output {
&mut self.deref_mut()[index]
}
}
impl<Mode: SmartStringMode> IndexMut<RangeTo<usize>> for SmartString<Mode> {
fn index_mut(&mut self, index: RangeTo<usize>) -> &mut Self::Output {
&mut self.deref_mut()[index]
}
}
impl<Mode: SmartStringMode> IndexMut<RangeFrom<usize>> for SmartString<Mode> {
fn index_mut(&mut self, index: RangeFrom<usize>) -> &mut Self::Output {
&mut self.deref_mut()[index]
}
}
impl<Mode: SmartStringMode> IndexMut<RangeFull> for SmartString<Mode> {
fn index_mut(&mut self, _index: RangeFull) -> &mut Self::Output {
self.deref_mut()
}
}
impl<Mode: SmartStringMode> IndexMut<RangeInclusive<usize>> for SmartString<Mode> {
fn index_mut(&mut self, index: RangeInclusive<usize>) -> &mut Self::Output {
&mut self.deref_mut()[index]
}
}
impl<Mode: SmartStringMode> IndexMut<RangeToInclusive<usize>> for SmartString<Mode> {
fn index_mut(&mut self, index: RangeToInclusive<usize>) -> &mut Self::Output {
&mut self.deref_mut()[index]
}
}
impl<Mode: SmartStringMode> From<&'_ str> for SmartString<Mode> {
fn from(string: &'_ str) -> Self {
if string.len() > MAX_INLINE {
Self::from_boxed(string.to_string().into())
} else {
Self::from_inline(string.into())
}
}
}
impl<Mode: SmartStringMode> From<&'_ mut str> for SmartString<Mode> {
fn from(string: &'_ mut str) -> Self {
if string.len() > MAX_INLINE {
Self::from_boxed(string.to_string().into())
} else {
Self::from_inline(string.deref().into())
}
}
}
impl<Mode: SmartStringMode> From<&'_ String> for SmartString<Mode> {
fn from(string: &'_ String) -> Self {
if string.len() > MAX_INLINE {
Self::from_boxed(string.clone().into())
} else {
Self::from_inline(string.deref().into())
}
}
}
impl<Mode: SmartStringMode> From<String> for SmartString<Mode> {
fn from(string: String) -> Self {
if string.len() > MAX_INLINE {
Self::from_boxed(string.into())
} else {
Self::from_inline(string.deref().into())
}
}
}
impl<Mode: SmartStringMode> From<Box<str>> for SmartString<Mode> {
fn from(string: Box<str>) -> Self {
if string.len() > MAX_INLINE {
String::from(string).into()
} else {
Self::from(&*string)
}
}
}
#[cfg(feature = "std")]
impl<Mode: SmartStringMode> From<Cow<'_, str>> for SmartString<Mode> {
fn from(string: Cow<'_, str>) -> Self {
if string.len() > MAX_INLINE {
String::from(string).into()
} else {
Self::from(&*string)
}
}
}
impl<'a, Mode: SmartStringMode> Extend<&'a str> for SmartString<Mode> {
fn extend<I: IntoIterator<Item = &'a str>>(&mut self, iter: I) {
for item in iter {
self.push_str(item);
}
}
}
impl<'a, Mode: SmartStringMode> Extend<&'a char> for SmartString<Mode> {
fn extend<I: IntoIterator<Item = &'a char>>(&mut self, iter: I) {
for item in iter {
self.push(*item);
}
}
}
impl<Mode: SmartStringMode> Extend<char> for SmartString<Mode> {
fn extend<I: IntoIterator<Item = char>>(&mut self, iter: I) {
for item in iter {
self.push(item);
}
}
}
impl<Mode: SmartStringMode> Extend<SmartString<Mode>> for SmartString<Mode> {
fn extend<I: IntoIterator<Item = SmartString<Mode>>>(&mut self, iter: I) {
for item in iter {
self.push_str(&item);
}
}
}
impl<Mode: SmartStringMode> Extend<String> for SmartString<Mode> {
fn extend<I: IntoIterator<Item = String>>(&mut self, iter: I) {
for item in iter {
self.push_str(&item);
}
}
}
impl<'a, Mode: SmartStringMode + 'a> Extend<&'a SmartString<Mode>> for SmartString<Mode> {
fn extend<I: IntoIterator<Item = &'a SmartString<Mode>>>(&mut self, iter: I) {
for item in iter {
self.push_str(item);
}
}
}
impl<'a, Mode: SmartStringMode> Extend<&'a String> for SmartString<Mode> {
fn extend<I: IntoIterator<Item = &'a String>>(&mut self, iter: I) {
for item in iter {
self.push_str(item);
}
}
}
impl<Mode: SmartStringMode> Add<Self> for SmartString<Mode> {
type Output = Self;
fn add(mut self, rhs: Self) -> Self::Output {
self.push_str(&rhs);
self
}
}
impl<Mode: SmartStringMode> Add<&'_ Self> for SmartString<Mode> {
type Output = Self;
fn add(mut self, rhs: &'_ Self) -> Self::Output {
self.push_str(rhs);
self
}
}
impl<Mode: SmartStringMode> Add<&'_ str> for SmartString<Mode> {
type Output = Self;
fn add(mut self, rhs: &'_ str) -> Self::Output {
self.push_str(rhs);
self
}
}
impl<Mode: SmartStringMode> Add<&'_ String> for SmartString<Mode> {
type Output = Self;
fn add(mut self, rhs: &'_ String) -> Self::Output {
self.push_str(rhs);
self
}
}
impl<Mode: SmartStringMode> Add<String> for SmartString<Mode> {
type Output = Self;
fn add(mut self, rhs: String) -> Self::Output {
self.push_str(&rhs);
self
}
}
impl<Mode: SmartStringMode> Add<SmartString<Mode>> for String {
type Output = Self;
fn add(mut self, rhs: SmartString<Mode>) -> Self::Output {
self.push_str(&rhs);
self
}
}
impl<Mode: SmartStringMode> FromIterator<Self> for SmartString<Mode> {
fn from_iter<I: IntoIterator<Item = Self>>(iter: I) -> Self {
let mut out = Self::new();
out.extend(iter.into_iter());
out
}
}
impl<Mode: SmartStringMode> FromIterator<String> for SmartString<Mode> {
fn from_iter<I: IntoIterator<Item = String>>(iter: I) -> Self {
let mut out = Self::new();
out.extend(iter.into_iter());
out
}
}
impl<'a, Mode: SmartStringMode + 'a> FromIterator<&'a Self> for SmartString<Mode> {
fn from_iter<I: IntoIterator<Item = &'a Self>>(iter: I) -> Self {
let mut out = Self::new();
out.extend(iter.into_iter());
out
}
}
impl<'a, Mode: SmartStringMode> FromIterator<&'a str> for SmartString<Mode> {
fn from_iter<I: IntoIterator<Item = &'a str>>(iter: I) -> Self {
let mut out = Self::new();
out.extend(iter.into_iter());
out
}
}
impl<'a, Mode: SmartStringMode> FromIterator<&'a String> for SmartString<Mode> {
fn from_iter<I: IntoIterator<Item = &'a String>>(iter: I) -> Self {
let mut out = Self::new();
out.extend(iter.into_iter());
out
}
}
impl<Mode: SmartStringMode> FromIterator<char> for SmartString<Mode> {
fn from_iter<I: IntoIterator<Item = char>>(iter: I) -> Self {
let mut out = Self::new();
for ch in iter {
out.push(ch);
}
out
}
}
impl<Mode: SmartStringMode> FromStr for SmartString<Mode> {
type Err = Infallible;
fn from_str(s: &str) -> Result<Self, Self::Err> {
Ok(Self::from(s))
}
}
impl<Mode: SmartStringMode> From<SmartString<Mode>> for String {
/// Unwrap a boxed [`String`][String], or copy an inline string into a new [`String`][String].
///
/// [String]: https://doc.rust-lang.org/std/string/struct.String.html
fn from(s: SmartString<Mode>) -> Self {
match s.cast_into() {
StringCastInto::Boxed(string) => string.into(),
StringCastInto::Inline(string) => string.to_string(),
}
}
}
impl<Mode: SmartStringMode> PartialEq<str> for SmartString<Mode> {
fn eq(&self, other: &str) -> bool {
self.as_str() == other
}
}
impl<Mode: SmartStringMode> PartialEq<&'_ str> for SmartString<Mode> {
fn eq(&self, other: &&str) -> bool {
self.as_str() == *other
}
}
impl<Mode: SmartStringMode> PartialEq<SmartString<Mode>> for &'_ str {
fn eq(&self, other: &SmartString<Mode>) -> bool {
other.eq(*self)
}
}
impl<Mode: SmartStringMode> PartialEq<SmartString<Mode>> for str {
fn eq(&self, other: &SmartString<Mode>) -> bool {
other.eq(self)
}
}
impl<Mode: SmartStringMode> PartialEq<String> for SmartString<Mode> {
fn eq(&self, other: &String) -> bool {
self.eq(other.as_str())
}
}
impl<Mode: SmartStringMode> PartialEq<SmartString<Mode>> for String {
fn eq(&self, other: &SmartString<Mode>) -> bool {
other.eq(self.as_str())
}
}
impl<Mode: SmartStringMode> PartialEq for SmartString<Mode> {
fn eq(&self, other: &Self) -> bool {
self.as_str() == other.as_str()
}
}
impl<Mode: SmartStringMode> Eq for SmartString<Mode> {}
impl<Mode: SmartStringMode> PartialOrd<str> for SmartString<Mode> {
fn partial_cmp(&self, other: &str) -> Option<Ordering> {
self.as_str().partial_cmp(other)
}
}
impl<Mode: SmartStringMode> PartialOrd for SmartString<Mode> {
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
self.partial_cmp(other.as_str())
}
}
impl<Mode: SmartStringMode> Ord for SmartString<Mode> {
fn cmp(&self, other: &Self) -> Ordering {
self.as_str().cmp(other.as_str())
}
}
impl<Mode: SmartStringMode> Hash for SmartString<Mode> {
fn hash<H: Hasher>(&self, state: &mut H) {
self.as_str().hash(state)
}
}
impl<Mode: SmartStringMode> Debug for SmartString<Mode> {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
Debug::fmt(self.as_str(), f)
}
}
impl<Mode: SmartStringMode> Display for SmartString<Mode> {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
Display::fmt(self.as_str(), f)
}
}
impl<Mode: SmartStringMode> Write for SmartString<Mode> {
fn write_str(&mut self, string: &str) -> Result<(), Error> {
self.push_str(string);
Ok(())
}
}
#[cfg(any(test, feature = "test"))]
#[allow(missing_docs)]
pub mod test;