Added a file_exists() function.

dlib/dir_nav/dir_nav_extensions.cpp

@@ -34,6 +34,23 @@ namespace dlib
         }
     }
 
+// ----------------------------------------------------------------------------------------
+
+    bool file_exists (
+        const std::string& filename
+    )
+    {
+        try
+        {
+            dlib::file temp(filename);
+            return true;
+        }
+        catch (file::file_not_found&)
+        {
+            return false;
+        }
+    }
+
 // ----------------------------------------------------------------------------------------
 
     directory get_parent_directory (

dlib/dir_nav/dir_nav_extensions.h

@@ -13,6 +13,12 @@
 namespace dlib
 {
 
+// ----------------------------------------------------------------------------------------
+
+    bool file_exists (
+        const std::string& filename
+    );
+
 // ----------------------------------------------------------------------------------------
 
     namespace implementation_details

dlib/dir_nav/dir_nav_extensions_abstract.h

@@ -10,6 +10,19 @@
 namespace dlib
 {
 
+// ----------------------------------------------------------------------------------------
+
+    bool file_exists (
+        const std::string& filename
+    );
+    /*!
+        ensures
+            - if (a file with the given filename exists) then
+                - returns true
+            - else
+                - returns false
+    !*/
+
 // ----------------------------------------------------------------------------------------
 
     template <typename T>