1 files changed, 10 insertions, 0 deletions
diff --git a/askama_derive/src/input.rs b/askama_derive/src/input.rs
index 72d5d20..c23d30f 100644
--- a/askama_derive/src/input.rs
+++ b/askama_derive/src/input.rs
@@ -4,6 +4,7 @@ use quote::ToTokens;
 
 use askama_shared::{Config, Syntax};
 
+use std::io::{self, Write};
 use std::path::PathBuf;
 
 use syn;
@@ -144,6 +145,15 @@ impl<'a> TemplateInput<'a> {
             _ => None,
         };
 
+        if parent.is_some() {
+            io::stderr()
+                .write_fmt(format_args!(
+                    "   --> in struct {}\n   = use of deprecated field '_parent'\n",
+                    ast.ident
+                ))
+                .unwrap();
+        }
+
         // Validate syntax
         let syntax = syntax.map_or_else(
             || config.syntaxes.get(config.default_syntax).unwrap(),