/rust/registry/src/index.crates.io-1949cf8c6b5b557f/sval_ref-2.19.0/src/lib.rs

Source
/*!
A variant of [`sval::Value`] for types that store references internally.

# Deriving [`ValueRef`]

Add the `ref` feature to `sval_derive`:

```toml
[dependencies.sval_derive]
version = "2.19.0"
features = ["ref"]
```

and include the `#[sval(ref)]` attribute when deriving `Value`:

```rust,ignore
#[derive(Value)]
#[sval(ref)]
pub struct MyData<'a> {
    #[sval(outer_ref)]
    data: &'a str,
}
```

Fields are streamed as computed by default.
Use the `#[sval(outer_ref)]` attribute for fields with external references like `&'a str`, and the `#[sval(inner_ref)]` attribute for fields with internal references like `Data<'a>`.
*/

#![doc(html_logo_url = "https://raw.githubusercontent.com/sval-rs/sval/main/asset/logo.svg")]
#![cfg_attr(not(test), no_std)]
#![deny(missing_docs)]

#[cfg(feature = "std")]
extern crate std;

#[cfg(all(feature = "alloc", not(feature = "std")))]
extern crate alloc;
#[cfg(all(feature = "alloc", not(feature = "std")))]
extern crate core;

#[cfg(all(feature = "alloc", not(feature = "std")))]
mod std {
    pub use crate::{
        alloc::{borrow, boxed, collections, string, vec},
        core::{convert, fmt, hash, marker, mem, ops, result, str, write},
    };
}

#[cfg(all(not(feature = "alloc"), not(feature = "std")))]
extern crate core as std;

mod seq;

/**
Stream a value through a stream.
*/
pub fn stream_ref<'sval>(
    stream: &mut (impl Stream<'sval> + ?Sized),
    value: impl ValueRef<'sval>,
) -> Result {
    value.stream_ref(stream)
}

/**
Wrap an [`sval::Value`] in a [`ValueRef`]
*/
pub fn to_ref<'sval, V: sval::Value + ?Sized>(value: &'sval V) -> Ref<&'sval V> {
    Ref::new(value)
}

use sval::{Result, Stream, Value};

/**
Adapt an [`sval::Value`] into a [`ValueRef`].
*/
#[repr(transparent)]
#[derive(Debug, Clone, Copy)]
pub struct Ref<V: ?Sized>(V);

impl<V> Ref<V> {
    /**
    Wrap a value.
    */
    pub fn new(value: V) -> Self {
        Ref(value)
    }

    /**
    Get a reference to the underlying value.
    */
    pub fn inner(&self) -> &V {
        &self.0
    }

    /**
    Take ownership of the underlying value.
    */
    pub fn into_inner(self) -> V {
        self.0
    }
}

impl<V: ?Sized> Ref<V> {
    /**
    Get a borrowed wrapper over a borrowed value.
    */
    pub fn new_borrowed<'a>(value: &'a V) -> &'a Ref<V> {
        // SAFETY: `&'a V` and `&'a Ref<V>` have the same ABI
        unsafe { &*(value as *const _ as *const Ref<V>) }
    }
}

impl<V: sval::Value> sval::Value for Ref<V> {
    fn stream<'sval, S: Stream<'sval> + ?Sized>(&'sval self, stream: &mut S) -> Result {
        self.0.stream(stream)
    }

    fn tag(&self) -> Option<sval::Tag> {
        self.0.tag()
    }

    fn to_bool(&self) -> Option<bool> {
        self.0.to_bool()
    }

    fn to_f32(&self) -> Option<f32> {
        self.0.to_f32()
    }

    fn to_f64(&self) -> Option<f64> {
        self.0.to_f64()
    }

    fn to_i8(&self) -> Option<i8> {
        self.0.to_i8()
    }

    fn to_i16(&self) -> Option<i16> {
        self.0.to_i16()
    }

    fn to_i32(&self) -> Option<i32> {
        self.0.to_i32()
    }

    fn to_i64(&self) -> Option<i64> {
        self.0.to_i64()
    }

    fn to_i128(&self) -> Option<i128> {
        self.0.to_i128()
    }

    fn to_u8(&self) -> Option<u8> {
        self.0.to_u8()
    }

    fn to_u16(&self) -> Option<u16> {
        self.0.to_u16()
    }

    fn to_u32(&self) -> Option<u32> {
        self.0.to_u32()
    }

    fn to_u64(&self) -> Option<u64> {
        self.0.to_u64()
    }

    fn to_u128(&self) -> Option<u128> {
        self.0.to_u128()
    }

    fn to_text(&self) -> Option<&str> {
        self.0.to_text()
    }

    fn to_binary(&self) -> Option<&[u8]> {
        self.0.to_binary()
    }
}

impl<'sval, V: sval::Value + ?Sized> ValueRef<'sval> for Ref<&'sval V> {
    fn stream_ref<S: Stream<'sval> + ?Sized>(&self, stream: &mut S) -> Result {
        self.0.stream(stream)
    }
}

/**
A producer of structured data that stores a reference internally.

This trait is a variant of [`Value`] for wrapper types that keep a reference to a value internally.
In `Value`, the `'sval` lifetime comes from the borrow of `&'sval self`. In `ValueRef`, it comes
from the `'sval` lifetime in the trait itself.
*/
pub trait ValueRef<'sval>: Value {
    /**
    Stream this value through a [`Stream`].
    */
    fn stream_ref<S: Stream<'sval> + ?Sized>(&self, stream: &mut S) -> Result;
}

macro_rules! impl_value_ref_forward {
    ({ $($r:tt)* } => $bind:ident => { $($forward:tt)* }) => {
        $($r)* {
            fn stream_ref<S: Stream<'sval> + ?Sized>(&self, stream: &mut S) -> Result {
                let $bind = self;
                ($($forward)*).stream_ref(stream)
            }
        }
    };
}

impl_value_ref_forward!({impl<'sval, 'a, T: ValueRef<'sval> + ?Sized> ValueRef<'sval> for &'a T} => x => { **x });

#[cfg(feature = "alloc")]
mod alloc_support {
    use super::*;

    use crate::std::boxed::Box;

    impl_value_ref_forward!({impl<'sval, T: ValueRef<'sval> + ?Sized> ValueRef<'sval> for Box<T>} => x => { **x });
}

#[cfg(test)]
mod test {
    use crate::ValueRef;
    pub(crate) use sval_test::{assert_tokens, Token};

    pub(crate) fn assert_tokens_ref<'sval>(
        value: impl ValueRef<'sval>,
        tokens: &[sval_test::Token<'sval>],
    ) {
        let mut actual = sval_test::TokenBuf::new();
        value.stream_ref(&mut actual).unwrap();

        assert_eq!(tokens, actual.as_tokens());
    }

    pub(crate) struct Ref<T>(pub(crate) T);

    impl<T: sval::Value> sval::Value for Ref<T> {
        fn stream<'sval, S: sval::Stream<'sval> + ?Sized>(
            &'sval self,
            stream: &mut S,
        ) -> sval::Result {
            self.0.stream(stream)
        }
    }

    impl<'sval, T: sval::Value + ?Sized> ValueRef<'sval> for Ref<&'sval T> {
        fn stream_ref<S: sval::Stream<'sval> + ?Sized>(&self, stream: &mut S) -> sval::Result {
            self.0.stream(stream)
        }
    }

    pub(crate) fn compat_case<'sval>(
        v: &'sval (impl sval::Value + ValueRef<'sval> + ?Sized),
        tokens: &[Token<'sval>],
    ) {
        assert_tokens_ref(v, tokens);
        assert_tokens(v, tokens);
    }
}

Coverage Report

Created: 2026-06-28 08:04

Line	Count	Source
1		/*!
2		A variant of [`sval::Value`] for types that store references internally.
3
4		# Deriving [`ValueRef`]
5
6		Add the `ref` feature to `sval_derive`:
7
8		```toml
9		[dependencies.sval_derive]
10		version = "2.19.0"
11		features = ["ref"]
12		```
13
14		and include the `#[sval(ref)]` attribute when deriving `Value`:
15
16		```rust,ignore
17		#[derive(Value)]
18		#[sval(ref)]
19		pub struct MyData<'a> {
20		#[sval(outer_ref)]
21		data: &'a str,
22		}
23		```
24
25		Fields are streamed as computed by default.
26		Use the `#[sval(outer_ref)]` attribute for fields with external references like `&'a str`, and the `#[sval(inner_ref)]` attribute for fields with internal references like `Data<'a>`.
27		*/
28
29		#![doc(html_logo_url = "https://raw.githubusercontent.com/sval-rs/sval/main/asset/logo.svg")]
30		#![cfg_attr(not(test), no_std)]
31		#![deny(missing_docs)]
32
33		#[cfg(feature = "std")]
34		extern crate std;
35
36		#[cfg(all(feature = "alloc", not(feature = "std")))]
37		extern crate alloc;
38		#[cfg(all(feature = "alloc", not(feature = "std")))]
39		extern crate core;
40
41		#[cfg(all(feature = "alloc", not(feature = "std")))]
42		mod std {
43		pub use crate::{
44		alloc::{borrow, boxed, collections, string, vec},
45		core::{convert, fmt, hash, marker, mem, ops, result, str, write},
46		};
47		}
48
49		#[cfg(all(not(feature = "alloc"), not(feature = "std")))]
50		extern crate core as std;
51
52		mod seq;
53
54		/**
55		Stream a value through a stream.
56		*/
57	0	pub fn stream_ref<'sval>(
58	0	stream: &mut (impl Stream<'sval> + ?Sized),
59	0	value: impl ValueRef<'sval>,
60	0	) -> Result {
61	0	value.stream_ref(stream)
62	0	} Unexecuted instantiation: sval_ref::stream_ref::<dyn sval_dynamic::stream::Stream, &sval_buffer::value::ValueSlice> Unexecuted instantiation: sval_ref::stream_ref::<dyn sval_dynamic::stream::Stream, &sval_buffer::fragments::TextBuf> Unexecuted instantiation: sval_ref::stream_ref::<dyn sval_dynamic::stream::Stream, &sval_buffer::fragments::BinaryBuf> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::tag::Extract, &sval_buffer::value::ValueSlice> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::tag::Extract, &sval_buffer::fragments::TextBuf> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::tag::Extract, &sval_buffer::fragments::BinaryBuf> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_f32::Extract, &sval_buffer::value::ValueSlice> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_f32::Extract, &sval_buffer::fragments::TextBuf> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_f32::Extract, &sval_buffer::fragments::BinaryBuf> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_f64::Extract, &sval_buffer::value::ValueSlice> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_f64::Extract, &sval_buffer::fragments::TextBuf> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_f64::Extract, &sval_buffer::fragments::BinaryBuf> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_bool::Extract, &sval_buffer::value::ValueSlice> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_bool::Extract, &sval_buffer::fragments::TextBuf> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_bool::Extract, &sval_buffer::fragments::BinaryBuf> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_i128::Extract, &sval_buffer::value::ValueSlice> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_i128::Extract, &sval_buffer::fragments::TextBuf> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_i128::Extract, &sval_buffer::fragments::BinaryBuf> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_text::Extract, &sval_buffer::value::ValueSlice> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_text::Extract, &sval_buffer::fragments::TextBuf> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_text::Extract, &sval_buffer::fragments::BinaryBuf> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_u128::Extract, &sval_buffer::value::ValueSlice> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_u128::Extract, &sval_buffer::fragments::TextBuf> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_u128::Extract, &sval_buffer::fragments::BinaryBuf> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_binary::Extract, &sval_buffer::value::ValueSlice> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_binary::Extract, &sval_buffer::fragments::TextBuf> Unexecuted instantiation: sval_ref::stream_ref::<sval::value::default_value::to_binary::Extract, &sval_buffer::fragments::BinaryBuf>
63
64		/**
65		Wrap an [`sval::Value`] in a [`ValueRef`]
66		*/
67		pub fn to_ref<'sval, V: sval::Value + ?Sized>(value: &'sval V) -> Ref<&'sval V> {
68		Ref::new(value)
69		}
70
71		use sval::{Result, Stream, Value};
72
73		/**
74		Adapt an [`sval::Value`] into a [`ValueRef`].
75		*/
76		#[repr(transparent)]
77		#[derive(Debug, Clone, Copy)]
78		pub struct Ref<V: ?Sized>(V);
79
80		impl<V> Ref<V> {
81		/**
82		Wrap a value.
83		*/
84		pub fn new(value: V) -> Self {
85		Ref(value)
86		}
87
88		/**
89		Get a reference to the underlying value.
90		*/
91		pub fn inner(&self) -> &V {
92		&self.0
93		}
94
95		/**
96		Take ownership of the underlying value.
97		*/
98		pub fn into_inner(self) -> V {
99		self.0
100		}
101		}
102
103		impl<V: ?Sized> Ref<V> {
104		/**
105		Get a borrowed wrapper over a borrowed value.
106		*/
107		pub fn new_borrowed<'a>(value: &'a V) -> &'a Ref<V> {
108		// SAFETY: `&'a V` and `&'a Ref<V>` have the same ABI
109		unsafe { &(value as const _ as *const Ref<V>) }
110		}
111		}
112
113		impl<V: sval::Value> sval::Value for Ref<V> {
114		fn stream<'sval, S: Stream<'sval> + ?Sized>(&'sval self, stream: &mut S) -> Result {
115		self.0.stream(stream)
116		}
117
118		fn tag(&self) -> Option<sval::Tag> {
119		self.0.tag()
120		}
121
122		fn to_bool(&self) -> Option<bool> {
123		self.0.to_bool()
124		}
125
126		fn to_f32(&self) -> Option<f32> {
127		self.0.to_f32()
128		}
129
130		fn to_f64(&self) -> Option<f64> {
131		self.0.to_f64()
132		}
133
134		fn to_i8(&self) -> Option<i8> {
135		self.0.to_i8()
136		}
137
138		fn to_i16(&self) -> Option<i16> {
139		self.0.to_i16()
140		}
141
142		fn to_i32(&self) -> Option<i32> {
143		self.0.to_i32()
144		}
145
146		fn to_i64(&self) -> Option<i64> {
147		self.0.to_i64()
148		}
149
150		fn to_i128(&self) -> Option<i128> {
151		self.0.to_i128()
152		}
153
154		fn to_u8(&self) -> Option<u8> {
155		self.0.to_u8()
156		}
157
158		fn to_u16(&self) -> Option<u16> {
159		self.0.to_u16()
160		}
161
162		fn to_u32(&self) -> Option<u32> {
163		self.0.to_u32()
164		}
165
166		fn to_u64(&self) -> Option<u64> {
167		self.0.to_u64()
168		}
169
170		fn to_u128(&self) -> Option<u128> {
171		self.0.to_u128()
172		}
173
174		fn to_text(&self) -> Option<&str> {
175		self.0.to_text()
176		}
177
178		fn to_binary(&self) -> Option<&[u8]> {
179		self.0.to_binary()
180		}
181		}
182
183		impl<'sval, V: sval::Value + ?Sized> ValueRef<'sval> for Ref<&'sval V> {
184		fn stream_ref<S: Stream<'sval> + ?Sized>(&self, stream: &mut S) -> Result {
185		self.0.stream(stream)
186		}
187		}
188
189		/**
190		A producer of structured data that stores a reference internally.
191
192		This trait is a variant of [`Value`] for wrapper types that keep a reference to a value internally.
193		In `Value`, the `'sval` lifetime comes from the borrow of `&'sval self`. In `ValueRef`, it comes
194		from the `'sval` lifetime in the trait itself.
195		*/
196		pub trait ValueRef<'sval>: Value {
197		/**
198		Stream this value through a [`Stream`].
199		*/
200		fn stream_ref<S: Stream<'sval> + ?Sized>(&self, stream: &mut S) -> Result;
201		}
202
203		macro_rules! impl_value_ref_forward {
204		({ $($r:tt)* } => $bind:ident => { $($forward:tt)* }) => {
205		$($r)* {
206	0	fn stream_ref<S: Stream<'sval> + ?Sized>(&self, stream: &mut S) -> Result {
207	0	let $bind = self;
208	0	($($forward)*).stream_ref(stream)
209	0	} Unexecuted instantiation: <&sval_buffer::fragments::TextBuf as sval_ref::ValueRef>::stream_ref::<dyn sval_dynamic::stream::Stream> Unexecuted instantiation: <&sval_buffer::fragments::TextBuf as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::tag::Extract> Unexecuted instantiation: <&sval_buffer::fragments::TextBuf as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_f32::Extract> Unexecuted instantiation: <&sval_buffer::fragments::TextBuf as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_f64::Extract> Unexecuted instantiation: <&sval_buffer::fragments::TextBuf as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_bool::Extract> Unexecuted instantiation: <&sval_buffer::fragments::TextBuf as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_i128::Extract> Unexecuted instantiation: <&sval_buffer::fragments::TextBuf as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_text::Extract> Unexecuted instantiation: <&sval_buffer::fragments::TextBuf as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_u128::Extract> Unexecuted instantiation: <&sval_buffer::fragments::TextBuf as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_binary::Extract> Unexecuted instantiation: <&sval_buffer::fragments::BinaryBuf as sval_ref::ValueRef>::stream_ref::<dyn sval_dynamic::stream::Stream> Unexecuted instantiation: <&sval_buffer::fragments::BinaryBuf as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::tag::Extract> Unexecuted instantiation: <&sval_buffer::fragments::BinaryBuf as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_f32::Extract> Unexecuted instantiation: <&sval_buffer::fragments::BinaryBuf as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_f64::Extract> Unexecuted instantiation: <&sval_buffer::fragments::BinaryBuf as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_bool::Extract> Unexecuted instantiation: <&sval_buffer::fragments::BinaryBuf as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_i128::Extract> Unexecuted instantiation: <&sval_buffer::fragments::BinaryBuf as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_text::Extract> Unexecuted instantiation: <&sval_buffer::fragments::BinaryBuf as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_u128::Extract> Unexecuted instantiation: <&sval_buffer::fragments::BinaryBuf as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_binary::Extract> Unexecuted instantiation: <&sval_buffer::value::ValueSlice as sval_ref::ValueRef>::stream_ref::<dyn sval_dynamic::stream::Stream> Unexecuted instantiation: <&sval_buffer::value::ValueSlice as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::tag::Extract> Unexecuted instantiation: <&sval_buffer::value::ValueSlice as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_f32::Extract> Unexecuted instantiation: <&sval_buffer::value::ValueSlice as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_f64::Extract> Unexecuted instantiation: <&sval_buffer::value::ValueSlice as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_bool::Extract> Unexecuted instantiation: <&sval_buffer::value::ValueSlice as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_i128::Extract> Unexecuted instantiation: <&sval_buffer::value::ValueSlice as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_text::Extract> Unexecuted instantiation: <&sval_buffer::value::ValueSlice as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_u128::Extract> Unexecuted instantiation: <&sval_buffer::value::ValueSlice as sval_ref::ValueRef>::stream_ref::<sval::value::default_value::to_binary::Extract>
210		}
211		};
212		}
213
214		impl_value_ref_forward!({impl<'sval, 'a, T: ValueRef<'sval> + ?Sized> ValueRef<'sval> for &'a T} => x => { **x });
215
216		#[cfg(feature = "alloc")]
217		mod alloc_support {
218		use super::*;
219
220		use crate::std::boxed::Box;
221
222		impl_value_ref_forward!({impl<'sval, T: ValueRef<'sval> + ?Sized> ValueRef<'sval> for Box<T>} => x => { **x });
223		}
224
225		#[cfg(test)]
226		mod test {
227		use crate::ValueRef;
228		pub(crate) use sval_test::{assert_tokens, Token};
229
230		pub(crate) fn assert_tokens_ref<'sval>(
231		value: impl ValueRef<'sval>,
232		tokens: &[sval_test::Token<'sval>],
233		) {
234		let mut actual = sval_test::TokenBuf::new();
235		value.stream_ref(&mut actual).unwrap();
236
237		assert_eq!(tokens, actual.as_tokens());
238		}
239
240		pub(crate) struct Ref<T>(pub(crate) T);
241
242		impl<T: sval::Value> sval::Value for Ref<T> {
243		fn stream<'sval, S: sval::Stream<'sval> + ?Sized>(
244		&'sval self,
245		stream: &mut S,
246		) -> sval::Result {
247		self.0.stream(stream)
248		}
249		}
250
251		impl<'sval, T: sval::Value + ?Sized> ValueRef<'sval> for Ref<&'sval T> {
252		fn stream_ref<S: sval::Stream<'sval> + ?Sized>(&self, stream: &mut S) -> sval::Result {
253		self.0.stream(stream)
254		}
255		}
256
257		pub(crate) fn compat_case<'sval>(
258		v: &'sval (impl sval::Value + ValueRef<'sval> + ?Sized),
259		tokens: &[Token<'sval>],
260		) {
261		assert_tokens_ref(v, tokens);
262		assert_tokens(v, tokens);
263		}
264		}