Remove function getErrorMessage, use std::optional instead

src/libs/antares/study/include/antares/study/parts/short-term-storage/AdditionalConstraint.h

@@ -20,6 +20,7 @@
  */
 
 #pragma once
+#include <optional>
 #include <set>
 #include <string>
 
@@ -37,19 +38,11 @@ struct AdditionalConstraint
 
     unsigned int globalIndex = 0;
 
-    bool validate() const;
+    std::optional<std::string> validate() const;
 
+private:
     bool isValidVariable() const;
-
     bool isValidOperatorType() const;
-
     bool isValidHoursRange() const;
-
-    mutable std::string error_message = "";
-
-    std::string getErrorMessage() const
-    {
-        return error_message;
-    }
 };
 } // namespace Antares::Data::ShortTermStorage

src/libs/antares/study/parts/short-term-storage/AdditionalConstraint.cpp

@@ -22,34 +22,29 @@
 
 namespace Antares::Data::ShortTermStorage
 {
-bool AdditionalConstraint::validate() const
+std::optional<std::string> AdditionalConstraint::validate() const
 {
     if (cluster_id.empty())
     {
-        error_message = "Cluster ID is empty.";
-        return false;
+        return "Cluster ID is empty.";
     }
 
     if (!isValidVariable())
     {
-        error_message = "Invalid variable type. Must be 'injection', 'withdrawal', or 'netting'.";
-        return false;
+        return "Invalid variable type. Must be 'injection', 'withdrawal', or 'netting'.";
     }
 
     if (!isValidOperatorType())
     {
-        error_message = "Invalid operator type. Must be 'less', 'equal', or 'greater'.";
-        return false;
+        return "Invalid operator type. Must be 'less', 'equal', or 'greater'.";
     }
 
     if (!isValidHoursRange())
     {
-        error_message = "Hours set contains invalid values. Must be between 1 and 168.";
-        return false;
+        return "Hours set contains invalid values. Must be between 1 and 168.";
     }
 
-    error_message.clear();
-    return true;
+    return {};
 }
 
 bool AdditionalConstraint::isValidHoursRange() const

src/libs/antares/study/parts/short-term-storage/container.cpp

@@ -125,10 +125,11 @@ bool STStorageInput::LoadConstraintsFromIniFile(const fs::path& parent_path)
             }
         }
 
-        if (!constraint.validate())
+        if (auto errorMaybe = constraint.validate())
         {
-            throw std::runtime_error("Invalid constraint in section: " + section->name + "\n"
-                                     + constraint.getErrorMessage());
+            logs.error() << "Invalid constraint in section: " << section->name;
+            logs.error() << errorMaybe.value();
+            return false;
         }
 
         auto it = std::find_if(storagesByIndex.begin(),
@@ -140,6 +141,7 @@ bool STStorageInput::LoadConstraintsFromIniFile(const fs::path& parent_path)
             logs.warning() << " from file " << pathIni;
             logs.warning() << "Constraint " << section->name
                            << " does not reference an existing cluster";
+            return false;
         }
         else
         {