3 files changed, 39 insertions, 0 deletions
diff --git a/utils/hash.h b/utils/hash.h
index 3a60a429..5d7f2010 100755
--- a/utils/hash.h
+++ b/utils/hash.h
@@ -51,4 +51,10 @@ struct murmur_hash_array
   }
 };
 
+// adds default val to table if key wasn't found, returns ref to val
+template <class H,class K>
+typename H::data_type & get_default(H &ht,K const& k,typename H::data_type const& v) {
+  return const_cast<typename H::data_type &>(ht.insert(typename H::value_type(k,v)).first->second);
+}
+
 #endif
diff --git a/utils/small_vector.h b/utils/small_vector.h
index 25c52359..ae1e5727 100644
--- a/utils/small_vector.h
+++ b/utils/small_vector.h
@@ -14,6 +14,7 @@
 #include <stdint.h>
 #include <new>
 #include <stdint.h>
+#include "swap_pod.h"
 //sizeof(T)/sizeof(T*)>1?sizeof(T)/sizeof(T*):1
 
 template <class T,int SV_MAX=2>
@@ -245,6 +246,10 @@ public:
     return !(a==b);
   }
 
+  void swap(Self& o) const {
+    swap_pod(*this,o);
+  }
+
  private:
   union StorageType {
     T vals[SV_MAX];
@@ -255,6 +260,11 @@ public:
   uint16_t capacity_;  // only defined when size_ > __SV_MAX_STATIC
 };
 
+template <class T,int SV_MAX>
+inline void swap(SmallVector<T,SV_MAX> &a,SmallVector<T,SV_MAX> &b) {
+  a.swap(b);
+}
+
 typedef SmallVector<int,2> SmallVectorInt;
 
 template <class T,int N>
diff --git a/utils/swap_pod.h b/utils/swap_pod.h
new file mode 100755
index 00000000..bb9a830d
--- /dev/null
+++ b/utils/swap_pod.h
@@ -0,0 +1,23 @@
+#ifndef SWAP_POD_H
+#define SWAP_POD_H
+
+//for swapping objects of the same concrete type where just swapping their bytes will work.  will at least work on plain old data.
+
+#include <algorithm> // not used, but people who use this will want to bring std::swap in anyway
+#include <cstring>
+
+template <class T>
+inline void swap_pod(T &a,T &b) {
+  using namespace std;
+  const unsigned s=sizeof(T);
+  char tmp[s];
+  void *pt=(void*)tmp;
+  void *pa=(void*)&a;
+  void *pb=(void*)&b;
+  memcpy(pt,pa,s);
+  memcpy(pa,pb,s);
+  memcpy(pb,pt,s);
+}
+
+
+#endif