add test before using Layout::from_size_align_unchecked to avoid UB (f…

…ixes #22)

src/copyset.rs

@@ -1,3 +1,4 @@
+#[cfg(test)]
 pub trait CopySet: Default + Clone {
     type Item: Copy + Eq + Ord + std::fmt::Display + std::fmt::Debug;
     type Iter: Iterator<Item = Self::Item>;
@@ -141,6 +142,7 @@ assert_eq!(a | &b, (1..6).collect());
 
 pub(crate) use impl_set_methods;
 
+#[cfg(test)]
 impl CopySet for std::collections::HashSet<u64> {
     type Item = u64;
     type Iter = std::collections::hash_set::IntoIter<u64>;
@@ -164,6 +166,7 @@ impl CopySet for std::collections::HashSet<u64> {
     }
 }
 
+#[cfg(test)]
 impl CopySet for std::collections::HashSet<u32> {
     type Item = u32;
     type Iter = std::collections::hash_set::IntoIter<u32>;

src/set64.rs

@@ -492,6 +492,7 @@ impl<'a, 'b, T: Fits64> std::ops::BitOr<&'b Set64<T>> for &'a Set64<T> {
     }
 }
 
+#[cfg(test)]
 impl<T: Fits64 + Eq + Ord + std::fmt::Debug + std::fmt::Display> crate::copyset::CopySet
     for Set64<T>
 {

src/setu32.rs

@@ -374,6 +374,7 @@ enum InternalMut<'a> {
     },
 }
 
+#[cfg(test)]
 impl crate::copyset::CopySet for SetU32 {
     type Item = u32;
     type Iter = iter::IntoIter;
@@ -1302,6 +1303,10 @@ fn bytes_for_capacity(sz: usize) -> usize {
     sz * 4 + std::mem::size_of::<S>() - 4
 }
 fn layout_for_capacity(sz: usize) -> std::alloc::Layout {
+    let size = bytes_for_capacity(sz);
+    if size >= usize::MAX / 2 {
+        panic!("tinyset size is too large: {}", sz);
+    }
     unsafe { std::alloc::Layout::from_size_align_unchecked(bytes_for_capacity(sz), 4) }
 }
 

src/setu64.rs

@@ -1281,6 +1281,7 @@ impl SetU64 {
     }
 }
 
+#[cfg(test)]
 impl crate::copyset::CopySet for SetU64 {
     type Item = u64;
     type Iter = IntoIter;
@@ -1383,7 +1384,11 @@ fn bytes_for_capacity(sz: usize) -> usize {
     sz * 8 + std::mem::size_of::<S>() - 8
 }
 fn layout_for_capacity(sz: usize) -> std::alloc::Layout {
-    unsafe { std::alloc::Layout::from_size_align_unchecked(bytes_for_capacity(sz), 8) }
+    let size = bytes_for_capacity(sz);
+    if size >= usize::MAX / 2 {
+        panic!("tinyset size is too large: {}", sz);
+    }
+    unsafe { std::alloc::Layout::from_size_align_unchecked(size, 8) }
 }
 
 impl Drop for SetU64 {

src/setusize.rs

@@ -210,6 +210,7 @@ fn serialize_deserialize() {
     assert_eq!(set, serde_json::from_str(&s).unwrap());
 }
 
+#[cfg(test)]
 impl crate::copyset::CopySet for SetUsize {
     type Item = usize;
     type Iter = IntoIter;