Add file_empty(), extend path_entry() to return size

1 files changed, 16 insertions, 0 deletions

diff --git a/libbutl/filesystem.ixx b/libbutl/filesystem.ixx
index eb9984b..a6fae64 100644
--- a/libbutl/filesystem.ixx
+++ b/libbutl/filesystem.ixx
@@ -7,9 +7,25 @@ namespace butl
   inline bool
   dir_empty (const dir_path& d)
   {
+    // @@ Could 0 size be a valid and faster way?
+    //
     return dir_iterator (d) == dir_iterator ();
   }
 
+  inline bool
+  file_empty (const path& f)
+  {
+    auto p (path_entry (f));
+
+    if (p.first && p.second.type == entry_type::regular)
+      return p.second.size == 0;
+
+    throw_generic_error (
+      p.first
+      ? (p.second.type == entry_type::directory ? EISDIR : EINVAL)
+      : ENOENT);
+  }
+
   inline rmdir_status
   try_rmdir_r (const dir_path& p, bool ignore_error)
   {