Disallow (with a nice fixit) the infix modifier on func decls, it is just validated

and ignored anyway.  It is still required on operator decls though.


Swift SVN r19978

Author: lattner

include/swift/AST/DiagnosticsSema.def

@@ -292,17 +292,13 @@ ERROR(operator_not_func,sema_tcd,none,
       "operators must be declared with 'func'", ())
 ERROR(redefining_builtin_operator,sema_tcd,none,
       "cannot declare a custom %0 '%1' operator", (StringRef, StringRef))
-
-ERROR(invalid_infix_input,sema_tcd,none,
-      "function with 'infix' specified must take a two element tuple as input",
-     ())
+ERROR(invalid_infix_on_func,sema_tcd,none,
+      "'infix' modifier is not required or allowed on func declarations", ())
 ERROR(attribute_requires_operator_identifier,sema_tcd,none,
       "'%0' requires a function with an operator identifier", (StringRef))
 ERROR(attribute_requires_single_argument,sema_tcd,none,
       "'%0' requires a function with one argument", (StringRef))
 
-ERROR(assignment_without_inout,sema_tcd,none,
-      "assignment operator must have an initial inout argument", ())
 ERROR(inout_cant_be_variadic,sema_tce,none,
       "inout arguments cannot be variadic", ())
 ERROR(inout_only_parameter,sema_tce,none,

lib/Sema/TypeCheckAttr.cpp

@@ -649,21 +649,20 @@ void AttributeChecker::checkOperatorAttribute(DeclAttribute *attr) {
     return;
   }
 
-  // Infix operator must be binary.
+  // Infix operator is only allowed on operator declarations, not on func.
   if (isa<InfixAttr>(attr)) {
-    if (!FD->isBinaryOperator()) {
-      TC.diagnose(attr->getLocation(), diag::invalid_infix_input);
-      attr->setInvalid();
-      return;
-    }
-  } else {
-    // Otherwise, must be unary.
-    if (!FD->isUnaryOperator()) {
-      TC.diagnose(attr->getLocation(), diag::attribute_requires_single_argument,
-                  attr->getAttrName());
-      attr->setInvalid();
-      return;
-    }
+    TC.diagnose(attr->getLocation(), diag::invalid_infix_on_func)
+      .fixItRemove(attr->getLocation());
+    attr->setInvalid();
+    return;
+  }
+
+  // Otherwise, must be unary.
+  if (!FD->isUnaryOperator()) {
+    TC.diagnose(attr->getLocation(), diag::attribute_requires_single_argument,
+                attr->getAttrName());
+    attr->setInvalid();
+    return;
   }
 }
 

stdlib/core/IntegerArithmetic.swift.gyb

@@ -60,7 +60,7 @@ func ${op}= <T: _IntegerArithmeticType>(inout lhs: T, rhs: T) {
 // protocol should be presented to users as part of SignedNumberType.
 public protocol _SignedNumberType : Comparable, IntegerLiteralConvertible {
   // Subtraction is a requirement for SignedNumberType
-  infix func - (lhs: Self, rhs: Self) -> Self
+  func - (lhs: Self, rhs: Self) -> Self
 }
 
 // SignedNumberType itself contains only operator requirements having

test/decl/operator/operators.swift

@@ -83,13 +83,13 @@ postfix operator -+- {}
 
 infix operator +-+= {}
 
-infix func +-+ (x: Int, y: Int) -> Int {}
+infix func +-+ (x: Int, y: Int) -> Int {} // expected-error {{'infix' modifier is not required or allowed on func declarations}}
 prefix func +-+ (x: Int) -> Int {}
 
 prefix func -+- (inout y: Int) -> Int {} // expected-note 2{{found this candidate}}
 postfix func -+- (inout x: Int) -> Int {} // expected-note 2{{found this candidate}}
 
-infix func +-+= (inout x: Int, y: Int) -> Int {}
+infix func +-+= (inout x: Int, y: Int) -> Int {} // expected-error {{'infix' modifier is not required or allowed on func declarations}}
 
 var n = 0