Support building without TR1.
Change-Id: Ib59e201198e1ff2621626ab80e6b6f2156f0d1d1
diff --git a/internal/ceres/collections_port.h b/internal/ceres/collections_port.h
index 88032a5..a356cc0 100644
--- a/internal/ceres/collections_port.h
+++ b/internal/ceres/collections_port.h
@@ -33,17 +33,41 @@
#ifndef CERES_INTERNAL_COLLECTIONS_PORT_H_
#define CERES_INTERNAL_COLLECTIONS_PORT_H_
-#if defined(_MSC_VER) && _MSC_VER <= 1600
-#include <unordered_map>
-#include <unordered_set>
+#if defined(CERES_NO_TR1)
+# include <map>
+# include <set>
#else
-#include <tr1/unordered_map>
-#include <tr1/unordered_set>
+# if defined(_MSC_VER) && _MSC_VER <= 1600
+# include <unordered_map>
+# include <unordered_set>
+# else
+# include <tr1/unordered_map>
+# include <tr1/unordered_set>
+# endif
#endif
#include <utility>
#include "ceres/integral_types.h"
#include "ceres/internal/port.h"
+// Some systems don't have access to TR1. In that case, substitute the hash
+// map/set with normal map/set. The price to pay is slightly slower speed for
+// some operations.
+#if defined(CERES_NO_TR1)
+
+namespace ceres {
+namespace internal {
+
+template<typename K, typename V>
+struct HashMap : map<K, V> {};
+
+template<typename K>
+struct HashSet : set<K> {};
+
+} // namespace internal
+} // namespace ceres
+
+#else
+
namespace ceres {
namespace internal {
@@ -138,4 +162,6 @@
CERES_HASH_NAMESPACE_END
+#endif // CERES_NO_TR1
+
#endif // CERES_INTERNAL_COLLECTIONS_PORT_H_
