Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

6 files changed, 647 insertions, 0 deletions

diff --git a/vendor/generic-array-0.12.4/tests/arr.rs b/vendor/generic-array-0.12.4/tests/arr.rs
new file mode 100644
index 000000000..c37b5d50f
--- /dev/null
+++ b/vendor/generic-array-0.12.4/tests/arr.rs
@@ -0,0 +1,27 @@
+#[macro_use]
+extern crate generic_array;
+extern crate typenum;
+
+#[test]
+fn empty_without_trailing_comma() {
+    let ar = arr![u8; ];
+    assert_eq!(format!("{:x}", ar), "");
+}
+
+#[test]
+fn empty_with_trailing_comma() {
+    let ar = arr![u8; , ];
+    assert_eq!(format!("{:x}", ar), "");
+}
+
+#[test]
+fn without_trailing_comma() {
+    let ar = arr![u8; 10, 20, 30];
+    assert_eq!(format!("{:x}", ar), "0a141e");
+}
+
+#[test]
+fn with_trailing_comma() {
+    let ar = arr![u8; 10, 20, 30, ];
+    assert_eq!(format!("{:x}", ar), "0a141e");
+}
diff --git a/vendor/generic-array-0.12.4/tests/generics.rs b/vendor/generic-array-0.12.4/tests/generics.rs
new file mode 100644
index 000000000..d48fe08c0
--- /dev/null
+++ b/vendor/generic-array-0.12.4/tests/generics.rs
@@ -0,0 +1,98 @@
+#![recursion_limit = "128"]
+
+#[macro_use]
+extern crate generic_array;
+
+use generic_array::typenum::consts::U4;
+
+use std::fmt::Debug;
+use std::ops::Add;
+
+use generic_array::{GenericArray, ArrayLength};
+use generic_array::sequence::*;
+use generic_array::functional::*;
+
+/// Example function using generics to pass N-length sequences and map them
+pub fn generic_map<S>(s: S)
+where
+    S: FunctionalSequence<i32>,            // `.map`
+    S::Item: Add<i32, Output = i32>,       // `x + 1`
+    S: MappedGenericSequence<i32, i32>,    // `i32` -> `i32`
+    MappedSequence<S, i32, i32>: Debug,    // println!
+{
+    let a = s.map(|x| x + 1);
+
+    println!("{:?}", a);
+}
+
+/// Complex example function using generics to pass N-length sequences, zip them, and then map that result.
+///
+/// If used with `GenericArray` specifically this isn't necessary
+pub fn generic_sequence_zip_sum<A, B>(a: A, b: B) -> i32
+where
+    A: FunctionalSequence<i32>,                                                                 // `.zip`
+    B: FunctionalSequence<i32, Length = A::Length>,                                             // `.zip`
+    A: MappedGenericSequence<i32, i32>,                                                         // `i32` -> `i32`
+    B: MappedGenericSequence<i32, i32, Mapped = MappedSequence<A, i32, i32>>,                   // `i32` -> `i32`, prove A and B can map to the same output
+    A::Item: Add<B::Item, Output = i32>,                                                        // `l + r`
+    MappedSequence<A, i32, i32>: MappedGenericSequence<i32, i32> + FunctionalSequence<i32>,     // `.map`
+    SequenceItem<MappedSequence<A, i32, i32>>: Add<i32, Output=i32>,                            // `x + 1`
+    MappedSequence<MappedSequence<A, i32, i32>, i32, i32>: Debug,                               // `println!`
+    MappedSequence<MappedSequence<A, i32, i32>, i32, i32>: FunctionalSequence<i32>,             // `.fold`
+    SequenceItem<MappedSequence<MappedSequence<A, i32, i32>, i32, i32>>: Add<i32, Output=i32>   // `x + a`, note the order
+{
+    let c = a.zip(b, |l, r| l + r).map(|x| x + 1);
+
+    println!("{:?}", c);
+
+    c.fold(0, |a, x| x + a)
+}
+
+/// Super-simple fixed-length i32 `GenericArray`s
+pub fn generic_array_plain_zip_sum(a: GenericArray<i32, U4>, b: GenericArray<i32, U4>) -> i32 {
+    a.zip(b, |l, r| l + r).map(|x| x + 1).fold(0, |a, x| x + a)
+}
+
+pub fn generic_array_variable_length_zip_sum<N>(a: GenericArray<i32, N>, b: GenericArray<i32, N>) -> i32
+where
+    N: ArrayLength<i32>,
+{
+    a.zip(b, |l, r| l + r).map(|x| x + 1).fold(0, |a, x| x + a)
+}
+
+pub fn generic_array_same_type_variable_length_zip_sum<T, N>(a: GenericArray<T, N>, b: GenericArray<T, N>) -> i32
+where
+    N: ArrayLength<T> + ArrayLength<<T as Add<T>>::Output>,
+    T: Add<T, Output=i32>,
+{
+    a.zip(b, |l, r| l + r).map(|x| x + 1).fold(0, |a, x| x + a)
+}
+
+/// Complex example using fully generic `GenericArray`s with the same length.
+///
+/// It's mostly just the repeated `Add` traits, which would be present in other systems anyway.
+pub fn generic_array_zip_sum<A, B, N: ArrayLength<A> + ArrayLength<B>>(a: GenericArray<A, N>, b: GenericArray<B, N>) -> i32
+where
+    A: Add<B>,
+    N: ArrayLength<<A as Add<B>>::Output> +
+        ArrayLength<<<A as Add<B>>::Output as Add<i32>>::Output>,
+    <A as Add<B>>::Output: Add<i32>,
+    <<A as Add<B>>::Output as Add<i32>>::Output: Add<i32, Output=i32>,
+{
+    a.zip(b, |l, r| l + r).map(|x| x + 1).fold(0, |a, x| x + a)
+}
+
+#[test]
+fn test_generics() {
+    generic_map(arr![i32; 1, 2, 3, 4]);
+
+    assert_eq!(generic_sequence_zip_sum(arr![i32; 1, 2, 3, 4], arr![i32; 2, 3, 4, 5]), 28);
+
+    assert_eq!(generic_array_plain_zip_sum(arr![i32; 1, 2, 3, 4], arr![i32; 2, 3, 4, 5]), 28);
+
+    assert_eq!(generic_array_variable_length_zip_sum(arr![i32; 1, 2, 3, 4], arr![i32; 2, 3, 4, 5]), 28);
+
+    assert_eq!(generic_array_same_type_variable_length_zip_sum(arr![i32; 1, 2, 3, 4], arr![i32; 2, 3, 4, 5]), 28);
+
+    assert_eq!(generic_array_zip_sum(arr![i32; 1, 2, 3, 4], arr![i32; 2, 3, 4, 5]), 28);
+}
\ No newline at end of file
diff --git a/vendor/generic-array-0.12.4/tests/hex.rs b/vendor/generic-array-0.12.4/tests/hex.rs
new file mode 100644
index 000000000..0882e9bb3
--- /dev/null
+++ b/vendor/generic-array-0.12.4/tests/hex.rs
@@ -0,0 +1,61 @@
+#[macro_use]
+extern crate generic_array;
+extern crate typenum;
+
+use generic_array::GenericArray;
+use std::str::from_utf8;
+use typenum::U2048;
+
+#[test]
+fn short_lower_hex() {
+    let ar = arr![u8; 10, 20, 30];
+    assert_eq!(format!("{:x}", ar), "0a141e");
+}
+
+#[test]
+fn short_upper_hex() {
+    let ar = arr![u8; 30, 20, 10];
+    assert_eq!(format!("{:X}", ar), "1E140A");
+}
+
+#[test]
+fn long_lower_hex() {
+    let ar = GenericArray::<u8, U2048>::default();
+    assert_eq!(format!("{:x}", ar), from_utf8(&[b'0'; 4096]).unwrap());
+}
+
+#[test]
+fn long_lower_hex_truncated() {
+    let ar = GenericArray::<u8, U2048>::default();
+    assert_eq!(format!("{:.3001x}", ar), from_utf8(&[b'0'; 3001]).unwrap());
+}
+
+#[test]
+fn long_upper_hex() {
+    let ar = GenericArray::<u8, U2048>::default();
+    assert_eq!(format!("{:X}", ar), from_utf8(&[b'0'; 4096]).unwrap());
+}
+
+#[test]
+fn long_upper_hex_truncated() {
+    let ar = GenericArray::<u8, U2048>::default();
+    assert_eq!(format!("{:.2777X}", ar), from_utf8(&[b'0'; 2777]).unwrap());
+}
+
+#[test]
+fn truncated_lower_hex() {
+    let ar = arr![u8; 10, 20, 30, 40, 50];
+    assert_eq!(format!("{:.2x}", ar), "0a");
+    assert_eq!(format!("{:.3x}", ar), "0a1");
+    assert_eq!(format!("{:.4x}", ar), "0a14");
+}
+
+#[test]
+fn truncated_upper_hex() {
+    let ar = arr![u8; 30, 20, 10, 17, 0];
+    assert_eq!(format!("{:.4X}", ar), "1E14");
+    assert_eq!(format!("{:.5X}", ar), "1E140");
+    assert_eq!(format!("{:.6X}", ar), "1E140A");
+    assert_eq!(format!("{:.7X}", ar), "1E140A1");
+    assert_eq!(format!("{:.8X}", ar), "1E140A11");
+}
diff --git a/vendor/generic-array-0.12.4/tests/import_name.rs b/vendor/generic-array-0.12.4/tests/import_name.rs
new file mode 100644
index 000000000..27653c9a8
--- /dev/null
+++ b/vendor/generic-array-0.12.4/tests/import_name.rs
@@ -0,0 +1,10 @@
+#[macro_use]
+extern crate generic_array as gen_arr;
+
+use gen_arr::typenum;
+
+#[test]
+fn test_different_crate_name() {
+    let _: gen_arr::GenericArray<u32, typenum::U4> = arr![u32; 0, 1, 2, 3];
+    let _: gen_arr::GenericArray<u32, typenum::U0> = arr![u32;];
+}
diff --git a/vendor/generic-array-0.12.4/tests/iter.rs b/vendor/generic-array-0.12.4/tests/iter.rs
new file mode 100644
index 000000000..47860d728
--- /dev/null
+++ b/vendor/generic-array-0.12.4/tests/iter.rs
@@ -0,0 +1,164 @@
+#[macro_use]
+extern crate generic_array;
+
+use std::cell::Cell;
+use std::ops::Drop;
+
+use generic_array::GenericArray;
+use generic_array::typenum::consts::U5;
+
+#[test]
+fn test_into_iter_as_slice() {
+    let array = arr![char; 'a', 'b', 'c'];
+    let mut into_iter = array.into_iter();
+    assert_eq!(into_iter.as_slice(), &['a', 'b', 'c']);
+    let _ = into_iter.next().unwrap();
+    assert_eq!(into_iter.as_slice(), &['b', 'c']);
+    let _ = into_iter.next().unwrap();
+    let _ = into_iter.next().unwrap();
+    assert_eq!(into_iter.as_slice(), &[]);
+}
+
+#[test]
+fn test_into_iter_as_mut_slice() {
+    let array = arr![char; 'a', 'b', 'c'];
+    let mut into_iter = array.into_iter();
+    assert_eq!(into_iter.as_slice(), &['a', 'b', 'c']);
+    into_iter.as_mut_slice()[0] = 'x';
+    into_iter.as_mut_slice()[1] = 'y';
+    assert_eq!(into_iter.next().unwrap(), 'x');
+    assert_eq!(into_iter.as_slice(), &['y', 'c']);
+}
+
+#[test]
+fn test_into_iter_debug() {
+    let array = arr![char; 'a', 'b', 'c'];
+    let into_iter = array.into_iter();
+    let debug = format!("{:?}", into_iter);
+    assert_eq!(debug, "GenericArrayIter(['a', 'b', 'c'])");
+}
+
+#[test]
+fn test_into_iter_clone() {
+    fn iter_equal<I: Iterator<Item = i32>>(it: I, slice: &[i32]) {
+        let v: Vec<i32> = it.collect();
+        assert_eq!(&v[..], slice);
+    }
+    let mut it = arr![i32; 1, 2, 3].into_iter();
+    iter_equal(it.clone(), &[1, 2, 3]);
+    assert_eq!(it.next(), Some(1));
+    let mut it = it.rev();
+    iter_equal(it.clone(), &[3, 2]);
+    assert_eq!(it.next(), Some(3));
+    iter_equal(it.clone(), &[2]);
+    assert_eq!(it.next(), Some(2));
+    iter_equal(it.clone(), &[]);
+    assert_eq!(it.next(), None);
+}
+
+#[test]
+fn test_into_iter_nth() {
+    let v = arr![i32; 0, 1, 2, 3, 4];
+    for i in 0..v.len() {
+        assert_eq!(v.clone().into_iter().nth(i).unwrap(), v[i]);
+    }
+    assert_eq!(v.clone().into_iter().nth(v.len()), None);
+
+    let mut iter = v.into_iter();
+    assert_eq!(iter.nth(2).unwrap(), v[2]);
+    assert_eq!(iter.nth(1).unwrap(), v[4]);
+}
+
+#[test]
+fn test_into_iter_last() {
+    let v = arr![i32; 0, 1, 2, 3, 4];
+    assert_eq!(v.into_iter().last().unwrap(), 4);
+    assert_eq!(arr![i32; 0].into_iter().last().unwrap(), 0);
+}
+
+#[test]
+fn test_into_iter_count() {
+    let v = arr![i32; 0, 1, 2, 3, 4];
+    assert_eq!(v.clone().into_iter().count(), 5);
+
+    let mut iter2 = v.into_iter();
+    iter2.next();
+    iter2.next();
+    assert_eq!(iter2.count(), 3);
+}
+
+#[test]
+fn test_into_iter_flat_map() {
+    assert!((0..5).flat_map(|i| arr![i32; 2 * i, 2 * i + 1]).eq(0..10));
+}
+
+#[test]
+fn test_into_iter_drops() {
+    struct R<'a> {
+       i: &'a Cell<usize>,
+    }
+
+    impl<'a> Drop for R<'a> {
+       fn drop(&mut self) {
+            self.i.set(self.i.get() + 1);
+        }
+    }
+
+    fn r(i: &Cell<usize>) -> R {
+        R {
+            i: i
+        }
+    }
+
+    fn v(i: &Cell<usize>) -> GenericArray<R, U5> {
+        arr![R; r(i), r(i), r(i), r(i), r(i)]
+    }
+
+    let i = Cell::new(0);
+    {
+        v(&i).into_iter();
+    }
+    assert_eq!(i.get(), 5);
+
+    let i = Cell::new(0);
+    {
+        let mut iter = v(&i).into_iter();
+        let _x = iter.next();
+        assert_eq!(i.get(), 0);
+        assert_eq!(iter.count(), 4);
+        assert_eq!(i.get(), 4);
+    }
+    assert_eq!(i.get(), 5);
+
+    let i = Cell::new(0);
+    {
+        let mut iter = v(&i).into_iter();
+        let _x = iter.nth(2);
+        assert_eq!(i.get(), 2);
+        let _y = iter.last();
+        assert_eq!(i.get(), 3);
+    }
+    assert_eq!(i.get(), 5);
+
+    let i = Cell::new(0);
+    for (index, _x) in v(&i).into_iter().enumerate() {
+        assert_eq!(i.get(), index);
+    }
+    assert_eq!(i.get(), 5);
+
+    let i = Cell::new(0);
+    for (index, _x) in v(&i).into_iter().rev().enumerate() {
+        assert_eq!(i.get(), index);
+    }
+    assert_eq!(i.get(), 5);
+}
+
+/*
+//TODO: Cover this
+#[allow(dead_code)]
+fn assert_covariance() {
+    fn into_iter<'new>(i: GenericArrayIter<&'static str, U10>) -> GenericArrayIter<&'new str, U10> {
+        i
+    }
+}
+*/
\ No newline at end of file
diff --git a/vendor/generic-array-0.12.4/tests/mod.rs b/vendor/generic-array-0.12.4/tests/mod.rs
new file mode 100644
index 000000000..6c6d9eb49
--- /dev/null
+++ b/vendor/generic-array-0.12.4/tests/mod.rs
@@ -0,0 +1,287 @@
+#![recursion_limit = "128"]
+#![no_std]
+#[macro_use]
+extern crate generic_array;
+use core::cell::Cell;
+use core::ops::{Add, Drop};
+use generic_array::GenericArray;
+use generic_array::functional::*;
+use generic_array::sequence::*;
+use generic_array::typenum::{U1, U3, U4, U97};
+
+#[test]
+fn test() {
+    let mut list97 = [0; 97];
+    for i in 0..97 {
+        list97[i] = i as i32;
+    }
+    let l: GenericArray<i32, U97> = GenericArray::clone_from_slice(&list97);
+    assert_eq!(l[0], 0);
+    assert_eq!(l[1], 1);
+    assert_eq!(l[32], 32);
+    assert_eq!(l[56], 56);
+}
+
+#[test]
+fn test_drop() {
+    #[derive(Clone)]
+    struct TestDrop<'a>(&'a Cell<u32>);
+
+    impl<'a> Drop for TestDrop<'a> {
+        fn drop(&mut self) {
+            self.0.set(self.0.get() + 1);
+        }
+    }
+
+    let drop_counter = Cell::new(0);
+    {
+        let _: GenericArray<TestDrop, U3> = arr![TestDrop; TestDrop(&drop_counter),
+                           TestDrop(&drop_counter),
+                           TestDrop(&drop_counter)];
+    }
+    assert_eq!(drop_counter.get(), 3);
+}
+
+#[test]
+fn test_arr() {
+    let test: GenericArray<u32, U3> = arr![u32; 1, 2, 3];
+    assert_eq!(test[1], 2);
+}
+
+#[test]
+fn test_copy() {
+    let test = arr![u32; 1, 2, 3];
+    let test2 = test;
+    // if GenericArray is not copy, this should fail as a use of a moved value
+    assert_eq!(test[1], 2);
+    assert_eq!(test2[0], 1);
+}
+
+#[derive(Debug, PartialEq, Eq)]
+struct NoClone<T>(T);
+
+#[test]
+fn test_from_slice() {
+    let arr = [1, 2, 3, 4];
+    let gen_arr = GenericArray::<_, U3>::from_slice(&arr[..3]);
+    assert_eq!(&arr[..3], gen_arr.as_slice());
+    let arr = [NoClone(1u32), NoClone(2), NoClone(3), NoClone(4)];
+    let gen_arr = GenericArray::<_, U3>::from_slice(&arr[..3]);
+    assert_eq!(&arr[..3], gen_arr.as_slice());
+}
+
+#[test]
+fn test_from_mut_slice() {
+    let mut arr = [1, 2, 3, 4];
+    {
+        let gen_arr = GenericArray::<_, U3>::from_mut_slice(&mut arr[..3]);
+        gen_arr[2] = 10;
+    }
+    assert_eq!(arr, [1, 2, 10, 4]);
+    let mut arr = [NoClone(1u32), NoClone(2), NoClone(3), NoClone(4)];
+    {
+        let gen_arr = GenericArray::<_, U3>::from_mut_slice(&mut arr[..3]);
+        gen_arr[2] = NoClone(10);
+    }
+    assert_eq!(arr, [NoClone(1), NoClone(2), NoClone(10), NoClone(4)]);
+}
+
+#[test]
+fn test_default() {
+    let arr = GenericArray::<u8, U1>::default();
+    assert_eq!(arr[0], 0);
+}
+
+#[test]
+fn test_from() {
+    let data = [(1, 2, 3), (4, 5, 6), (7, 8, 9)];
+    let garray: GenericArray<(usize, usize, usize), U3> = data.into();
+    assert_eq!(&data, garray.as_slice());
+}
+
+#[test]
+fn test_unit_macro() {
+    let arr = arr![f32; 3.14];
+    assert_eq!(arr[0], 3.14);
+}
+
+#[test]
+fn test_empty_macro() {
+    let _arr = arr![f32;];
+}
+
+#[test]
+fn test_cmp() {
+    arr![u8; 0x00].cmp(&arr![u8; 0x00]);
+}
+
+/// This test should cause a helpful compile error if uncommented.
+// #[test]
+// fn test_empty_macro2(){
+//     let arr = arr![];
+// }
+#[cfg(feature = "serde")]
+mod impl_serde {
+    extern crate serde_json;
+
+    use generic_array::GenericArray;
+    use generic_array::typenum::U6;
+
+    #[test]
+    fn test_serde_implementation() {
+        let array: GenericArray<f64, U6> = arr![f64; 0.0, 5.0, 3.0, 7.07192, 76.0, -9.0];
+        let string = serde_json::to_string(&array).unwrap();
+        assert_eq!(string, "[0.0,5.0,3.0,7.07192,76.0,-9.0]");
+
+        let test_array: GenericArray<f64, U6> = serde_json::from_str(&string).unwrap();
+        assert_eq!(test_array, array);
+    }
+}
+
+#[test]
+fn test_map() {
+    let b: GenericArray<i32, U4> = GenericArray::generate(|i| i as i32 * 4).map(|x| x - 3);
+
+    assert_eq!(b, arr![i32; -3, 1, 5, 9]);
+}
+
+#[test]
+fn test_zip() {
+    let a: GenericArray<_, U4> = GenericArray::generate(|i| i + 1);
+    let b: GenericArray<_, U4> = GenericArray::generate(|i| i as i32 * 4);
+
+    // Uses reference and non-reference arguments
+    let c = (&a).zip(b, |r, l| *r as i32 + l);
+
+    assert_eq!(c, arr![i32; 1, 6, 11, 16]);
+}
+
+#[test]
+#[should_panic]
+fn test_from_iter_short() {
+    use core::iter::repeat;
+
+    let a: GenericArray<_, U4> = repeat(11).take(3).collect();
+
+    assert_eq!(a, arr![i32; 11, 11, 11, 0]);
+}
+
+#[test]
+fn test_from_iter() {
+    use core::iter::{once, repeat};
+
+    let a: GenericArray<_, U4> = repeat(11).take(3).chain(once(0)).collect();
+
+    assert_eq!(a, arr![i32; 11, 11, 11, 0]);
+}
+
+#[test]
+fn test_sizes() {
+    #![allow(dead_code)]
+    use core::mem::{size_of, size_of_val};
+
+    #[derive(Debug, Copy, Clone)]
+    #[repr(C)]
+    #[repr(packed)]
+    struct Test {
+        t: u16,
+        s: u32,
+        r: u16,
+        f: u16,
+        o: u32,
+    }
+
+    assert_eq!(size_of::<Test>(), 14);
+
+    assert_eq!(size_of_val(&arr![u8; 1, 2, 3]), size_of::<u8>() * 3);
+    assert_eq!(size_of_val(&arr![u32; 1]), size_of::<u32>() * 1);
+    assert_eq!(size_of_val(&arr![u64; 1, 2, 3, 4]), size_of::<u64>() * 4);
+
+    assert_eq!(size_of::<GenericArray<Test, U97>>(), size_of::<Test>() * 97);
+}
+
+#[test]
+fn test_append() {
+    let a = arr![i32; 1, 2, 3];
+
+    let b = a.append(4);
+
+    assert_eq!(b, arr![i32; 1, 2, 3, 4]);
+}
+
+#[test]
+fn test_prepend() {
+    let a = arr![i32; 1, 2, 3];
+
+    let b = a.prepend(4);
+
+    assert_eq!(b, arr![i32; 4, 1, 2, 3]);
+}
+
+#[test]
+fn test_pop() {
+    let a = arr![i32; 1, 2, 3, 4];
+
+    let (init, last) = a.pop_back();
+
+    assert_eq!(init, arr![i32; 1, 2, 3]);
+    assert_eq!(last, 4);
+
+    let (head, tail) = a.pop_front();
+
+    assert_eq!(head, 1);
+    assert_eq!(tail, arr![i32; 2, 3, 4]);
+}
+
+#[test]
+fn test_split() {
+    let a = arr![i32; 1, 2, 3, 4];
+
+    let (b, c) = a.split();
+
+    assert_eq!(b, arr![i32; 1]);
+    assert_eq!(c, arr![i32; 2, 3, 4]);
+
+    let (e, f) = a.split();
+
+    assert_eq!(e, arr![i32; 1, 2]);
+    assert_eq!(f, arr![i32; 3, 4]);
+}
+
+#[test]
+fn test_concat() {
+    let a = arr![i32; 1, 2];
+    let b = arr![i32; 3, 4];
+
+    let c = a.concat(b);
+
+    assert_eq!(c, arr![i32; 1, 2, 3, 4]);
+
+    let (d, e) = c.split();
+
+    assert_eq!(d, arr![i32; 1]);
+    assert_eq!(e, arr![i32; 2, 3, 4]);
+}
+
+#[test]
+fn test_fold() {
+    let a = arr![i32; 1, 2, 3, 4];
+
+    assert_eq!(10, a.fold(0, |a, x| a + x));
+}
+
+fn sum_generic<S>(s: S) -> i32
+where
+    S: FunctionalSequence<i32>,
+    S::Item: Add<i32, Output = i32>, // `+`
+    i32: Add<S::Item, Output = i32>, // reflexive
+{
+    s.fold(0, |a, x| a + x)
+}
+
+#[test]
+fn test_sum() {
+    let a = sum_generic(arr![i32; 1, 2, 3, 4]);
+
+    assert_eq!(a, 10);
+}