Add feature gate

1 files changed, 7 insertions, 2 deletions

diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index ee895fb1a96..af7e4a6855f 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -163,6 +163,8 @@ const KNOWN_FEATURES: &'static [(&'static str, &'static str, Status)] = &[
 
     // Allows the definition recursive static items.
     ("static_recursion", "1.3.0", Active),
+// Allows default type parameters to influence type inference.
+    ("default_type_parameter_fallback", "1.3.0", Active)
 ];
 // (changing above list without updating src/doc/reference.md makes @cmr sad)
 
@@ -341,7 +343,8 @@ pub struct Features {
     /// #![feature] attrs for non-language (library) features
     pub declared_lib_features: Vec<(InternedString, Span)>,
     pub const_fn: bool,
-    pub static_recursion: bool
+    pub static_recursion: bool,
+    pub default_type_parameter_fallback: bool,
 }
 
 impl Features {
@@ -366,7 +369,8 @@ impl Features {
             declared_stable_lang_features: Vec::new(),
             declared_lib_features: Vec::new(),
             const_fn: false,
-            static_recursion: false
+            static_recursion: false,
+            default_type_parameter_fallback: false,
         }
     }
 }
@@ -865,6 +869,7 @@ fn check_crate_inner<F>(cm: &CodeMap, span_handler: &SpanHandler,
         declared_lib_features: unknown_features,
         const_fn: cx.has_feature("const_fn"),
         static_recursion: cx.has_feature("static_recursion")
+        default_type_parameter_fallback: cx.has_feature("default_type_parameter_fallback"),
     }
 }