use hash_map for paths; much faster builds

1 files changed, 12 insertions, 0 deletions

diff --git a/src/hash_map.h b/src/hash_map.h
new file mode 100644
index 0000000..820f773
--- /dev/null
+++ b/src/hash_map.h
@@ -0,0 +1,12 @@
+#include <ext/hash_map>
+
+using __gnu_cxx::hash_map;
+
+namespace __gnu_cxx {
+template<>
+struct hash<std::string> {
+  size_t operator()(const std::string& s) const {
+    return hash<const char*>()(s.c_str());
+  }
+};
+}