4 files changed, 7 insertions, 10 deletions
diff --git a/src/libutil/archive.cc b/src/libutil/archive.cc
index ea1deb924e67..f71229d8fdd6 100644
--- a/src/libutil/archive.cc
+++ b/src/libutil/archive.cc
@@ -29,7 +29,7 @@ const std::string narVersionMagic1 = "nix-archive-1";
 
 static string caseHackSuffix = "~nix~case~hack~";
 
-PathFilter defaultPathFilter;
+PathFilter defaultPathFilter = [](const Path &) { return true; };
 
 
 static void dumpContents(const Path & path, size_t size,
diff --git a/src/libutil/archive.hh b/src/libutil/archive.hh
index 607ebf8b28f9..8a15e849c7b8 100644
--- a/src/libutil/archive.hh
+++ b/src/libutil/archive.hh
@@ -44,13 +44,6 @@ namespace nix {
 
      `+' denotes string concatenation. */
 
-struct PathFilter
-{
-    virtual ~PathFilter() { }
-    virtual bool operator () (const Path & path) { return true; }
-};
-
-extern PathFilter defaultPathFilter;
 
 void dumpPath(const Path & path, Sink & sink,
     PathFilter & filter = defaultPathFilter);
diff --git a/src/libutil/hash.hh b/src/libutil/hash.hh
index d83049b02368..fd7a61df8e46 100644
--- a/src/libutil/hash.hh
+++ b/src/libutil/hash.hh
@@ -93,8 +93,6 @@ Hash hashFile(HashType ht, const Path & path);
 
 /* Compute the hash of the given path.  The hash is defined as
    (essentially) hashString(ht, dumpPath(path)). */
-struct PathFilter;
-extern PathFilter defaultPathFilter;
 typedef std::pair<Hash, unsigned long long> HashResult;
 HashResult hashPath(HashType ht, const Path & path,
     PathFilter & filter = defaultPathFilter);
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index fccf5d854800..63a93f2ca6a7 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -481,4 +481,10 @@ struct MaintainCount
 std::pair<unsigned short, unsigned short> getWindowSize();
 
 
+/* Used in various places. */
+typedef std::function<bool(const Path & path)> PathFilter;
+
+extern PathFilter defaultPathFilter;
+
+
 }