BLI: add StringRefNull.c_str() method

This should be used whenever you rely on the fact, that the
returned pointer points to the beginning of a null-terminated array.

source/blender/blenkernel/intern/simulation.cc

@@ -399,7 +399,7 @@ static void add_missing_particle_states(Simulation *simulation, Span<std::string
       continue;
     }
 
-    BKE_simulation_state_add(simulation, SIM_STATE_TYPE_PARTICLES, name.data());
+    BKE_simulation_state_add(simulation, SIM_STATE_TYPE_PARTICLES, name.c_str());
   }
 }
 

source/blender/blenlib/BLI_string_ref.hh

@@ -187,7 +187,7 @@ class StringRefNull : public StringRefBase {
    * Reference a std::string. Remember that when the std::string is destructed, the StringRefNull
    * will point to uninitialized memory.
    */
-  StringRefNull(const std::string &str) : StringRefNull(str.data())
+  StringRefNull(const std::string &str) : StringRefNull(str.c_str())
   {
   }
 
@@ -200,6 +200,16 @@ class StringRefNull : public StringRefBase {
     BLI_assert(index <= size_);
     return data_[index];
   }
+
+  /**
+   * Returns the beginning of a null-terminated char array.
+   *
+   * This is like ->data(), but can only be called on a StringRefNull.
+   */
+  const char *c_str() const
+  {
+    return data_;
+  }
 };
 
 /**

source/blender/nodes/NOD_derived_node_tree.hh

@@ -477,7 +477,7 @@ inline Span<const DNode *> DerivedNodeTree::nodes() const
 
 inline Span<const DNode *> DerivedNodeTree::nodes_by_type(StringRefNull idname) const
 {
-  const bNodeType *nodetype = nodeTypeFind(idname.data());
+  const bNodeType *nodetype = nodeTypeFind(idname.c_str());
   return this->nodes_by_type(nodetype);
 }
 

source/blender/nodes/NOD_node_tree_multi_function.hh

@@ -240,7 +240,7 @@ class MFNetworkBuilderBase {
     BLI_STATIC_ASSERT((std::is_base_of_v<fn::MultiFunction, T>), "");
     void *buffer = common_.resources.linear_allocator().allocate(sizeof(T), alignof(T));
     T *fn = new (buffer) T(std::forward<Args>(args)...);
-    common_.resources.add(destruct_ptr<T>(fn), fn->name().data());
+    common_.resources.add(destruct_ptr<T>(fn), fn->name().c_str());
     return *fn;
   }
 };

source/blender/nodes/NOD_node_tree_ref.hh

@@ -405,7 +405,7 @@ inline Span<const NodeRef *> NodeTreeRef::nodes() const
 
 inline Span<const NodeRef *> NodeTreeRef::nodes_by_type(StringRefNull idname) const
 {
-  const bNodeType *nodetype = nodeTypeFind(idname.data());
+  const bNodeType *nodetype = nodeTypeFind(idname.c_str());
   return this->nodes_by_type(nodetype);
 }