Skip to content

feat: support fake variadic when length 1 not included #51

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
alice-i-cecile merged 5 commits into from
Jan 15, 2026
Merged

feat: support fake variadic when length 1 not included #51

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
8fa9e10
feat: support fake variadic when length 1 not included
kingwingfly Dec 18, 2025
f38fee1
fix typo
kingwingfly Dec 18, 2025
a2995fa
fix bug
kingwingfly Dec 18, 2025
44384c0
add tests
kingwingfly Jan 14, 2026
8f935bd
fix typo
kingwingfly Jan 14, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 3 additions & 0 deletions Cargo.toml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,9 @@ syn = "2.0"
quote = "1.0"
proc-macro2 = "1.0"

[dev-dependencies]
static_assertions = "1.1"

[workspace]
exclude = ["benches", "compile_fail", "tools/compile_fail_utils"]
members = ["errors", ".", "benches"]
Expand Down
2 changes: 1 addition & 1 deletion examples/demonstrations/all_tuples.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
//! An example of using `all_tuples!`

#![cfg_attr(any(docsrs), feature(rustdoc_internals))]
#![cfg_attr(docsrs, feature(rustdoc_internals))]

use variadics_please::all_tuples;

Expand Down
118 changes: 82 additions & 36 deletions src/lib.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -28,17 +28,15 @@ impl Parse for AllTuples {
let macro_ident = input.parse::<Ident>()?;
input.parse::<Comma>()?;
let start = input.parse::<LitInt>()?.base10_parse()?;

if start > 1 && fake_variadic {
return Err(Error::new(
input.span(),
"#[doc(fake_variadic)] only works when the tuple with length one is included",
));
}

input.parse::<Comma>()?;
let end_span = input.span();
let end = input.parse::<LitInt>()?.base10_parse()?;
input.parse::<Comma>()?;

if end < start {
return Err(Error::new(end_span, "`start` should <= `end`"));
}

let mut idents = vec![input.parse::<Ident>()?];
while input.parse::<Comma>().is_ok() {
idents.push(input.parse::<Ident>()?);
Expand Down Expand Up @@ -182,13 +180,20 @@ pub fn all_tuples(input: TokenStream) -> TokenStream {
})
.collect::<Vec<_>>();
let macro_ident = &input.macro_ident;
let invocations = (input.start..=input.end).map(|n| {
let ident_tuples = choose_ident_tuples(&input, &ident_tuples, n);
let attrs = attrs(&input, n);
quote! {
#macro_ident!(#attrs #ident_tuples);
}
});
let invocations = (input.start..=input.end)
.chain(if input.fake_variadic && input.start > 1 {
// chain n = 1
vec![1]
} else {
vec![]
})
.map(|n| {
let ident_tuples = choose_ident_tuples(&input, &ident_tuples, n);
let attrs = attrs(&input, n);
quote! {
#macro_ident!(#attrs #ident_tuples);
}
});
TokenStream::from(quote! {
#(
#invocations
Expand Down Expand Up @@ -262,13 +267,19 @@ pub fn all_tuples_enumerated(input: TokenStream) -> TokenStream {
})
.collect::<Vec<_>>();
let macro_ident = &input.macro_ident;
let invocations = (input.start..=input.end).map(|n| {
let ident_tuples = choose_ident_tuples_enumerated(&input, &ident_tuples, n);
let attrs = attrs(&input, n);
quote! {
#macro_ident!(#attrs #ident_tuples);
}
});
let invocations = (input.start..=input.end)
.chain(if input.fake_variadic && input.start > 1 {
vec![1]
} else {
vec![]
})
.map(|n| {
let ident_tuples = choose_ident_tuples_enumerated(&input, &ident_tuples, n);
let attrs = attrs(&input, n);
quote! {
#macro_ident!(#attrs #ident_tuples);
}
});
TokenStream::from(quote! {
#(
#invocations
Expand Down Expand Up @@ -408,13 +419,19 @@ pub fn all_tuples_with_size(input: TokenStream) -> TokenStream {
})
.collect::<Vec<_>>();
let macro_ident = &input.macro_ident;
let invocations = (input.start..=input.end).map(|n| {
let ident_tuples = choose_ident_tuples(&input, &ident_tuples, n);
let attrs = attrs(&input, n);
quote! {
#macro_ident!(#n, #attrs #ident_tuples);
}
});
let invocations = (input.start..=input.end)
.chain(if input.fake_variadic && input.start > 1 {
vec![1]
} else {
vec![]
})
.map(|n| {
let ident_tuples = choose_ident_tuples(&input, &ident_tuples, n);
let attrs = attrs(&input, n);
quote! {
#macro_ident!(#n, #attrs #ident_tuples);
}
});
TokenStream::from(quote! {
#(
#invocations
Expand Down Expand Up @@ -476,8 +493,8 @@ fn choose_ident_tuples_enumerated(
}
}

fn to_ident_tuple(idents: impl Iterator<Item = Ident>, len: usize) -> TokenStream2 {
if len < 2 {
fn to_ident_tuple(idents: impl Iterator<Item = Ident>, generic_num: usize) -> TokenStream2 {
if generic_num < 2 {
quote! { #(#idents)* }
} else {
quote! { (#(#idents),*) }
Expand Down Expand Up @@ -505,14 +522,43 @@ fn attrs(input: &AllTuples, n: usize) -> TokenStream2 {
if n == 1 {
let doc = LitStr::new(
&format!(
"This trait is implemented for tuples down to {} up to {} items long.",
input.start, input.end
"This trait is implemented for tuple{s1} {range} item{s2} long.",
range = if input.start == input.end {
format!("exactly {}", input.start)
} else {
format!(
"{down}up to {up}",
down = if input.start != 0 {
format!("down to {} ", input.start)
} else {
"".to_string()
},
up = input.end
)
},
s1 = if input.end > input.start { "s" } else { "" },
s2 = if input.end >= input.start && input.end > 1 {
"s"
} else {
""
}
),
Span2::call_site(),
);
quote! {
#[cfg_attr(#cfg, doc(fake_variadic))]
#[cfg_attr(#cfg, doc = #doc)]
if input.start <= 1 && input.end >= 1 {
// n == 1 and it's included
quote! {
#[cfg_attr(#cfg, doc(fake_variadic))]
#[cfg_attr(#cfg, doc = #doc)]
}
} else {
// n == 1 but it's not included,
// only generate if #cfg
quote! {
#[cfg(#cfg)]
#[doc(fake_variadic)]
#[doc = #doc]
}
}
} else {
quote! { #[cfg_attr(#cfg, doc(hidden))] }
Expand Down
72 changes: 72 additions & 0 deletions tests/basic_all_tuples.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,72 @@
#![allow(missing_docs, dead_code)]

use static_assertions::{assert_impl_one, assert_not_impl_any};
use variadics_please::all_tuples;

trait Foo {}

macro_rules! foo {
($($t: ident),* $(,)?) => {
impl<$($t),*> Foo for ($($t,)*) {}
};
}

// [0, 2]
all_tuples!(foo, 0, 2, T);

// no {3}

// [4, 5]
all_tuples!(foo, 4, 5, T);

trait Bar {}

macro_rules! bar {
($(($t1: ident, $t2: ident)),* $(,)?) => {
impl<$($t1,)* $($t2),*> Bar for ($(($t1, $t2),)*) {}
};
}

// [0, 2]
all_tuples!(bar, 0, 2, T, U);

// no {3}

// [4, 5]
all_tuples!(bar, 4, 5, T, U);

#[test]
fn basic_test() {
// 0
assert_impl_one!((): Foo);
// 1
assert_impl_one!(((),): Foo);
// 2
assert_impl_one!(((), ()): Foo);
// no 3
assert_not_impl_any!(((), (), ()): Foo);

// 4
assert_impl_one!(((), (), (), ()): Foo);
// 5
assert_impl_one!(((), (), (), (), ()): Foo);
// no 6
assert_not_impl_any!(((), (), (), (), (), ()): Foo);

// ((T, U), ..)
// 0
assert_impl_one!((): Bar);
// 1
assert_impl_one!((((), ()),): Bar);
// 2
assert_impl_one!((((),()), ((),())): Bar);
// no 3
assert_not_impl_any!((((),()), ((),()), ((),())): Bar);

// 4
assert_impl_one!((((),()), ((),()), ((),()), ((),())): Bar);
// 5
assert_impl_one!((((),()), ((),()), ((),()), ((),()), ((),())): Bar);
// no 6
assert_not_impl_any!((((),()), ((),()), ((),()), ((),()), ((),()), ((),())): Bar);
}
72 changes: 72 additions & 0 deletions tests/basic_all_tuples_enumerated.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,72 @@
#![allow(missing_docs, dead_code)]

use static_assertions::{assert_impl_one, assert_not_impl_any};
use variadics_please::all_tuples_enumerated;

trait Foo {}

macro_rules! foo {
($(($_: literal, $t: ident)),* $(,)?) => {
impl<$($t),*> Foo for ($($t,)*) {}
};
}

// [0, 2]
all_tuples_enumerated!(foo, 0, 2, T);

// no {3}

// [4, 5]
all_tuples_enumerated!(foo, 4, 5, T);

trait Bar {}

macro_rules! bar {
($(($_: literal, $t1: ident, $t2: ident)),* $(,)?) => {
impl<$($t1,)* $($t2),*> Bar for ($(($t1, $t2),)*) {}
};
}

// [0, 2]
all_tuples_enumerated!(bar, 0, 2, T, U);

// no {3}

// [4, 5]
all_tuples_enumerated!(bar, 4, 5, T, U);

#[test]
fn basic_test() {
// 0
assert_impl_one!((): Foo);
// 1
assert_impl_one!(((),): Foo);
// 2
assert_impl_one!(((), ()): Foo);
// no 3
assert_not_impl_any!(((), (), ()): Foo);

// 4
assert_impl_one!(((), (), (), ()): Foo);
// 5
assert_impl_one!(((), (), (), (), ()): Foo);
// no 6
assert_not_impl_any!(((), (), (), (), (), ()): Foo);

// ((T, U), ..)
// 0
assert_impl_one!((): Bar);
// 1
assert_impl_one!((((), ()),): Bar);
// 2
assert_impl_one!((((),()), ((),())): Bar);
// no 3
assert_not_impl_any!((((),()), ((),()), ((),())): Bar);

// 4
assert_impl_one!((((),()), ((),()), ((),()), ((),())): Bar);
// 5
assert_impl_one!((((),()), ((),()), ((),()), ((),()), ((),())): Bar);
// no 6
assert_not_impl_any!((((),()), ((),()), ((),()), ((),()), ((),()), ((),())): Bar);
}
Loading
Loading