Re-export heapsize_derive from heapsize
diff --git a/examples/heapsize/example/Cargo.toml b/examples/heapsize/example/Cargo.toml
index ebfaeb9..85c7699 100644
--- a/examples/heapsize/example/Cargo.toml
+++ b/examples/heapsize/example/Cargo.toml
@@ -7,4 +7,3 @@
 
 [dependencies]
 heapsize = { path = "../heapsize" }
-heapsize_derive = { path = "../heapsize_derive" }
diff --git a/examples/heapsize/example/src/main.rs b/examples/heapsize/example/src/main.rs
index f273a3e..9332b11 100644
--- a/examples/heapsize/example/src/main.rs
+++ b/examples/heapsize/example/src/main.rs
@@ -1,5 +1,4 @@
 use heapsize::HeapSize;
-use heapsize_derive::HeapSize;
 
 #[derive(HeapSize)]
 struct Demo<'a, T: ?Sized> {
diff --git a/examples/heapsize/heapsize/Cargo.toml b/examples/heapsize/heapsize/Cargo.toml
index f0183b4..27bb954 100644
--- a/examples/heapsize/heapsize/Cargo.toml
+++ b/examples/heapsize/heapsize/Cargo.toml
@@ -4,3 +4,6 @@
 authors = ["David Tolnay <dtolnay@gmail.com>"]
 edition = "2018"
 publish = false
+
+[dependencies]
+heapsize_derive = { path = "../heapsize_derive" }
diff --git a/examples/heapsize/heapsize/src/lib.rs b/examples/heapsize/heapsize/src/lib.rs
index 8b4ce03..30bb6d6 100644
--- a/examples/heapsize/heapsize/src/lib.rs
+++ b/examples/heapsize/heapsize/src/lib.rs
@@ -1,5 +1,7 @@
 use std::mem;
 
+pub use heapsize_derive::*;
+
 pub trait HeapSize {
     /// Total number of bytes of heap memory owned by `self`.
     ///