Preset::config() returns a weak reference to the shared configuration.

src/GUI/Preset.cpp

@@ -44,6 +44,11 @@ Slic3r::Config Preset::dirty_config() {
     return result;
 }
 
+config_ref Preset::config() {
+    std::weak_ptr<Slic3r::Config> result { this->_dirty_config };
+    return result;
+}
+
 config_ptr Preset::load_config() {
     if (this->loaded()) return this->_dirty_config;
 

src/GUI/Preset.hpp

@@ -78,6 +78,9 @@ public:
     /// Retrieve a copy of the loaded version of the configuration with any options applied.
     Slic3r::Config dirty_config(); 
 
+    /// Retrieve a shared (cast through a weak) pointer. 
+    config_ref config();
+
     /// Pass-through to Slic3r::Config, returns whether or not a config was loaded.
     bool loaded() { return !this->_config->empty(); }
 

xs/src/libslic3r/Config.hpp

@@ -33,6 +33,7 @@ public:
 
 class Config;
 using config_ptr = std::shared_ptr<Config>;
+using config_ref = std::weak_ptr<Config>;
 
 class Config {
 public: