Add generic helper functions for models which have the same table definition.

src/helpers.zig

@@ -0,0 +1,29 @@
+const std = @import("std");
+
+/// Simple ModelFromSql and ModelToSql functions for models which have the same table definition.
+pub fn TableModel(comptime Model: type, comptime TableShape: type) type {
+	// Get fields of the model, which must be the same as the table shape.
+	const fields = std.meta.fields(Model);
+
+	return struct {
+		/// Simply copy all fields from model to table.
+		pub fn copyModelToTable(_model: Model) !TableShape {
+			var _table: TableShape = undefined;
+			inline for (fields) |modelField| {
+				// Copy each field of the model to the table.
+				@field(_table, modelField.name) = @field(_model, modelField.name);
+			}
+			return _table;
+		}
+
+		/// Simply copy all fields from table to model.
+		pub fn copyTableToModel(_table: TableShape) !Model {
+			var _model: Model = undefined;
+			inline for (fields) |tableField| {
+				// Copy each field of the table to the model.
+				@field(_model, tableField.name) = @field(_table, tableField.name);
+			}
+			return _model;
+		}
+	};
+}

src/root.zig

@@ -17,3 +17,5 @@ pub const SqlParams = _sql.SqlParams;
 pub const conditions = @import("conditions.zig");
 
 pub const errors = @import("errors.zig");
+
+pub const helpers = @import("helpers.zig");

tests/composite.zig

@@ -66,8 +66,8 @@ const CompositeModelRepository = zrm.Repository(CompositeModel, CompositeModelTa
 
 	.key = &[_][]const u8{"firstcol", "secondcol"},
 
-	.fromSql = &modelFromSql,
+	.fromSql = &zrm.helpers.TableModel(CompositeModel, CompositeModelTable).copyTableToModel,
-	.toSql = &modelToSql,
+	.toSql = &zrm.helpers.TableModel(CompositeModel, CompositeModelTable).copyModelToTable,
 });