execution_profiles: Extended API with pointee_to_builder()

This method will be crucial for convenient execution profiles in
Cpp-Rust-driver implementation.

Author: wprzytula

scylla/src/transport/execution_profile.rs

@@ -406,6 +406,20 @@ pub(crate) struct ExecutionProfileInner {
     pub(crate) speculative_execution_policy: Option<Arc<dyn SpeculativeExecutionPolicy>>,
 }
 
+impl ExecutionProfileInner {
+    /// Creates a builder having all options set to the same as set in this ExecutionProfileInner.
+    pub(crate) fn to_builder(&self) -> ExecutionProfileBuilder {
+        ExecutionProfileBuilder {
+            request_timeout: Some(self.request_timeout),
+            consistency: Some(self.consistency),
+            serial_consistency: Some(self.serial_consistency),
+            load_balancing_policy: Some(self.load_balancing_policy.clone()),
+            retry_policy: Some(self.retry_policy.clone()),
+            speculative_execution_policy: Some(self.speculative_execution_policy.clone()),
+        }
+    }
+}
+
 impl ExecutionProfile {
     pub(crate) fn new_from_inner(inner: ExecutionProfileInner) -> Self {
         Self(Arc::new(inner))
@@ -425,14 +439,7 @@ impl ExecutionProfile {
 
     /// Creates a builder having all options set to the same as set in this ExecutionProfile.
     pub fn to_builder(&self) -> ExecutionProfileBuilder {
-        ExecutionProfileBuilder {
-            request_timeout: Some(self.0.request_timeout),
-            consistency: Some(self.0.consistency),
-            serial_consistency: Some(self.0.serial_consistency),
-            load_balancing_policy: Some(self.0.load_balancing_policy.clone()),
-            retry_policy: Some(self.0.retry_policy.clone()),
-            speculative_execution_policy: Some(self.0.speculative_execution_policy.clone()),
-        }
+        self.0.to_builder()
     }
 
     /// Returns a new handle to this ExecutionProfile.
@@ -468,6 +475,11 @@ impl ExecutionProfileHandle {
         self.0 .0.load_full()
     }
 
+    /// Creates a builder having all options set to the same as set in the ExecutionProfile pointed by this handle.
+    pub fn pointee_to_builder(&self) -> ExecutionProfileBuilder {
+        self.0 .0.load().to_builder()
+    }
+
     /// Makes the handle point to a new execution profile.
     /// All entities (queries/Session) holding this handle will reflect the change.
     pub fn map_to_another_profile(&mut self, profile: ExecutionProfile) {