diff --git a/src/common.rs b/src/common.rs
index 39294155c..c57357af8 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -5,3 +5,31 @@ pub use uint::*;
 pub use bytes::*;
 pub use vector::*;
 pub use sha3::*;
+
+#[macro_export]
+macro_rules! map {
+	( $( $x:expr => $y:expr ),* ) => {
+		vec![ $( ($x, $y) ),* ].into_iter().collect::<BTreeMap<_, _>>()
+	}
+}
+
+#[macro_export]
+macro_rules! mapx {
+	( $( $x:expr => $y:expr ),* ) => {
+		vec![ $( ( From::from($x), From::from($y) ) ),* ].into_iter().collect::<BTreeMap<_, _>>()
+	}
+}
+
+#[macro_export]
+macro_rules! x {
+	( $x:expr ) => {
+		From::from($x)
+	}
+}
+
+#[macro_export]
+macro_rules! xx {
+	( $x:expr ) => {
+		From::from(From::from($x))
+	}
+}