[C++11] More 'nullptr' conversion or in some cases just using a boolean check instead...

[oota-llvm.git] / include / llvm / Support / Casting.h

diff --git a/include/llvm/Support/Casting.h b/include/llvm/Support/Casting.h
index 0c71882a77b1fc1952faf52c2e5c0420c035bc26..beed31a4084f60f2383586bf05382ba2fed1923a 100644 (file)
--- a/include/llvm/Support/Casting.h
+++ b/include/llvm/Support/Casting.h
@@ -15,6 +15,7 @@
 #ifndef LLVM_SUPPORT_CASTING_H
 #define LLVM_SUPPORT_CASTING_H
 
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/type_traits.h"
 #include <cassert>
 
@@ -36,9 +37,13 @@ template<typename From> struct simplify_type {
 };
 
 template<typename From> struct simplify_type<const From> {
-  typedef const From SimpleType;
-  static SimpleType &getSimplifiedValue(const From &Val) {
-    return simplify_type<From>::getSimplifiedValue(static_cast<From&>(Val));
+  typedef typename simplify_type<From>::SimpleType NonConstSimpleType;
+  typedef typename add_const_past_pointer<NonConstSimpleType>::type
+    SimpleType;
+  typedef typename add_lvalue_reference_if_not_pointer<SimpleType>::type
+    RetType;
+  static RetType getSimplifiedValue(const From& Val) {
+    return simplify_type<From>::getSimplifiedValue(const_cast<From&>(Val));
   }
 };
 
@@ -54,11 +59,8 @@ struct isa_impl {
 
 /// \brief Always allow upcasts, and perform no dynamic check for them.
 template <typename To, typename From>
-struct isa_impl<To, From,
-                typename llvm::enable_if_c<
-                  llvm::is_base_of<To, From>::value
-                >::type
-               > {
+struct isa_impl<
+    To, From, typename std::enable_if<std::is_base_of<To, From>::value>::type> {
   static inline bool doit(const From &) { return true; }
 };
 
@@ -81,6 +83,13 @@ template <typename To, typename From> struct isa_impl_cl<To, From*> {
   }
 };
 
+template <typename To, typename From> struct isa_impl_cl<To, From*const> {
+  static inline bool doit(const From *Val) {
+    assert(Val && "isa<> used on a null pointer");
+    return isa_impl<To, From>::doit(*Val);
+  }
+};
+
 template <typename To, typename From> struct isa_impl_cl<To, const From*> {
   static inline bool doit(const From *Val) {
     assert(Val && "isa<> used on a null pointer");
@@ -102,7 +111,7 @@ struct isa_impl_wrap {
   static bool doit(const From &Val) {
     return isa_impl_wrap<To, SimpleFrom,
       typename simplify_type<SimpleFrom>::SimpleType>::doit(
-                          simplify_type<From>::getSimplifiedValue(Val));
+                          simplify_type<const From>::getSimplifiedValue(Val));
   }
 };
 
@@ -120,8 +129,9 @@ struct isa_impl_wrap<To, FromTy, FromTy> {
 //  if (isa<Type>(myVal)) { ... }
 //
 template <class X, class Y>
-inline bool isa(const Y &Val) {
-  return isa_impl_wrap<X, Y, typename simplify_type<Y>::SimpleType>::doit(Val);
+LLVM_ATTRIBUTE_UNUSED_RESULT inline bool isa(const Y &Val) {
+  return isa_impl_wrap<X, const Y,
+                       typename simplify_type<const Y>::SimpleType>::doit(Val);
 }
 
 //===----------------------------------------------------------------------===//
@@ -178,7 +188,7 @@ struct cast_retty {
 //
 template<class To, class From, class SimpleFrom> struct cast_convert_val {
   // This is not a simple type, use the template to simplify it...
-  static typename cast_retty<To, From>::ret_type doit(const From &Val) {
+  static typename cast_retty<To, From>::ret_type doit(From &Val) {
     return cast_convert_val<To, SimpleFrom,
       typename simplify_type<SimpleFrom>::SimpleType>::doit(
                           simplify_type<From>::getSimplifiedValue(Val));
@@ -194,7 +204,10 @@ template<class To, class FromTy> struct cast_convert_val<To,FromTy,FromTy> {
   }
 };
 
-
+template <class X> struct is_simple_type {
+  static const bool value =
+      std::is_same<X, typename simplify_type<X>::SimpleType>::value;
+};
 
 // cast<X> - Return the argument parameter cast to the specified type.  This
 // casting operator asserts that the type is correct, so it does not return null
@@ -204,18 +217,35 @@ template<class To, class FromTy> struct cast_convert_val<To,FromTy,FromTy> {
 //  cast<Instruction>(myVal)->getParent()
 //
 template <class X, class Y>
-inline typename cast_retty<X, Y>::ret_type cast(const Y &Val) {
+inline typename std::enable_if<!is_simple_type<Y>::value,
+                               typename cast_retty<X, const Y>::ret_type>::type
+cast(const Y &Val) {
+  assert(isa<X>(Val) && "cast<Ty>() argument of incompatible type!");
+  return cast_convert_val<
+      X, const Y, typename simplify_type<const Y>::SimpleType>::doit(Val);
+}
+
+template <class X, class Y>
+inline typename cast_retty<X, Y>::ret_type cast(Y &Val) {
   assert(isa<X>(Val) && "cast<Ty>() argument of incompatible type!");
   return cast_convert_val<X, Y,
                           typename simplify_type<Y>::SimpleType>::doit(Val);
 }
 
+template <class X, class Y>
+inline typename cast_retty<X, Y *>::ret_type cast(Y *Val) {
+  assert(isa<X>(Val) && "cast<Ty>() argument of incompatible type!");
+  return cast_convert_val<X, Y*,
+                          typename simplify_type<Y*>::SimpleType>::doit(Val);
+}
+
 // cast_or_null<X> - Functionally identical to cast, except that a null value is
 // accepted.
 //
 template <class X, class Y>
-inline typename cast_retty<X, Y*>::ret_type cast_or_null(Y *Val) {
-  if (Val == 0) return 0;
+LLVM_ATTRIBUTE_UNUSED_RESULT inline typename cast_retty<X, Y *>::ret_type
+cast_or_null(Y *Val) {
+  if (!Val) return nullptr;
   assert(isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!");
   return cast<X>(Val);
 }
@@ -230,16 +260,31 @@ inline typename cast_retty<X, Y*>::ret_type cast_or_null(Y *Val) {
 //
 
 template <class X, class Y>
-inline typename cast_retty<X, Y>::ret_type dyn_cast(const Y &Val) {
-  return isa<X>(Val) ? cast<X, Y>(Val) : 0;
+LLVM_ATTRIBUTE_UNUSED_RESULT inline typename std::enable_if<
+    !is_simple_type<Y>::value, typename cast_retty<X, const Y>::ret_type>::type
+dyn_cast(const Y &Val) {
+  return isa<X>(Val) ? cast<X>(Val) : nullptr;
+}
+
+template <class X, class Y>
+LLVM_ATTRIBUTE_UNUSED_RESULT inline typename cast_retty<X, Y>::ret_type
+dyn_cast(Y &Val) {
+  return isa<X>(Val) ? cast<X>(Val) : nullptr;
+}
+
+template <class X, class Y>
+LLVM_ATTRIBUTE_UNUSED_RESULT inline typename cast_retty<X, Y *>::ret_type
+dyn_cast(Y *Val) {
+  return isa<X>(Val) ? cast<X>(Val) : nullptr;
 }
 
 // dyn_cast_or_null<X> - Functionally identical to dyn_cast, except that a null
 // value is accepted.
 //
 template <class X, class Y>
-inline typename cast_retty<X, Y*>::ret_type dyn_cast_or_null(Y *Val) {
-  return (Val && isa<X>(Val)) ? cast<X>(Val) : 0;
+LLVM_ATTRIBUTE_UNUSED_RESULT inline typename cast_retty<X, Y *>::ret_type
+dyn_cast_or_null(Y *Val) {
+  return (Val && isa<X>(Val)) ? cast<X>(Val) : nullptr;
 }
 
 } // End llvm namespace