1894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman//===-- llvm/Support/Casting.h - Allow flexible, checked, casts -*- C++ -*-===// 2894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 3894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// The LLVM Compiler Infrastructure 4894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 5894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// This file is distributed under the University of Illinois Open Source 6894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// License. See LICENSE.TXT for details. 7894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 8894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman//===----------------------------------------------------------------------===// 9894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 10894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// This file defines the isa<X>(), cast<X>(), dyn_cast<X>(), cast_or_null<X>(), 11894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// and dyn_cast_or_null<X>() templates. 12894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 13894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman//===----------------------------------------------------------------------===// 14894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 15894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman#ifndef LLVM_SUPPORT_CASTING_H 16894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman#define LLVM_SUPPORT_CASTING_H 17894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 18894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman#include <cassert> 19894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 20894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumannamespace llvm { 21894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 22894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman//===----------------------------------------------------------------------===// 23894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// isa<x> Support Templates 24894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman//===----------------------------------------------------------------------===// 25894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 26894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// Define a template that can be specialized by smart pointers to reflect the 27894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// fact that they are automatically dereferenced, and are not involved with the 28894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// template selection process... the default implementation is a noop. 29894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 30894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate<typename From> struct simplify_type { 31894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman typedef From SimpleType; // The real type this represents... 32894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 33894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman // An accessor to get the real value... 34894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman static SimpleType &getSimplifiedValue(From &Val) { return Val; } 35894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 36894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 37894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate<typename From> struct simplify_type<const From> { 38894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman typedef const From SimpleType; 39894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman static SimpleType &getSimplifiedValue(const From &Val) { 40894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman return simplify_type<From>::getSimplifiedValue(static_cast<From&>(Val)); 41894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 42894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 43894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 4419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// The core of the implementation of isa<X> is here; To and From should be 4519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// the names of classes. This template can be specialized to customize the 4619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// implementation of isa<> without rewriting it from scratch. 47894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate <typename To, typename From> 48894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumanstruct isa_impl { 49894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman static inline bool doit(const From &Val) { 50894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman return To::classof(&Val); 51894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 52894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 53894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 5419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumantemplate <typename To, typename From> struct isa_impl_cl { 5519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman static inline bool doit(const From &Val) { 5619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return isa_impl<To, From>::doit(Val); 57894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 58894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 59894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 6019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumantemplate <typename To, typename From> struct isa_impl_cl<To, const From> { 6119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman static inline bool doit(const From &Val) { 6219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return isa_impl<To, From>::doit(Val); 63894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 64894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 65894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 6619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumantemplate <typename To, typename From> struct isa_impl_cl<To, From*> { 6719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman static inline bool doit(const From *Val) { 6819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return isa_impl<To, From>::doit(*Val); 69894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 70894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 71894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 7219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumantemplate <typename To, typename From> struct isa_impl_cl<To, const From*> { 7319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman static inline bool doit(const From *Val) { 7419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return isa_impl<To, From>::doit(*Val); 75894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 76894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 77894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 7819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumantemplate <typename To, typename From> struct isa_impl_cl<To, const From*const> { 7919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman static inline bool doit(const From *Val) { 8019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return isa_impl<To, From>::doit(*Val); 81894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 82894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 83894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 8419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumantemplate<typename To, typename From, typename SimpleFrom> 8519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstruct isa_impl_wrap { 8619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // When From != SimplifiedType, we can simplify the type some more by using 8719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // the simplify_type template. 8819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman static bool doit(const From &Val) { 8919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return isa_impl_wrap<To, SimpleFrom, 9019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman typename simplify_type<SimpleFrom>::SimpleType>::doit( 9119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman simplify_type<From>::getSimplifiedValue(Val)); 9219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 9319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman}; 9419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman 9519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumantemplate<typename To, typename FromTy> 9619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumanstruct isa_impl_wrap<To, FromTy, FromTy> { 9719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman // When From == SimpleType, we are as simple as we are going to get. 9819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman static bool doit(const FromTy &Val) { 9919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return isa_impl_cl<To,FromTy>::doit(Val); 100894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 101894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 102894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 10319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// isa<X> - Return true if the parameter to the template is an instance of the 10419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// template type argument. Used like this: 10519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// 10619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// if (isa<Type>(myVal)) { ... } 10719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// 108894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate <class X, class Y> 109894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumaninline bool isa(const Y &Val) { 11019bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return isa_impl_wrap<X, Y, typename simplify_type<Y>::SimpleType>::doit(Val); 111894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman} 112894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 113894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman//===----------------------------------------------------------------------===// 114894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// cast<x> Support Templates 115894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman//===----------------------------------------------------------------------===// 116894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 117894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate<class To, class From> struct cast_retty; 118894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 119894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 120894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// Calculate what type the 'cast' function should return, based on a requested 121894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// type of To and a source type of From. 122894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate<class To, class From> struct cast_retty_impl { 123894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman typedef To& ret_type; // Normal case, return Ty& 124894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 125894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate<class To, class From> struct cast_retty_impl<To, const From> { 126894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman typedef const To &ret_type; // Normal case, return Ty& 127894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 128894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 129894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate<class To, class From> struct cast_retty_impl<To, From*> { 130894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman typedef To* ret_type; // Pointer arg case, return Ty* 131894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 132894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 133894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate<class To, class From> struct cast_retty_impl<To, const From*> { 134894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman typedef const To* ret_type; // Constant pointer arg case, return const Ty* 135894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 136894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 137894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate<class To, class From> struct cast_retty_impl<To, const From*const> { 138894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman typedef const To* ret_type; // Constant pointer arg case, return const Ty* 139894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 140894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 141894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 142894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate<class To, class From, class SimpleFrom> 143894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumanstruct cast_retty_wrap { 144894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman // When the simplified type and the from type are not the same, use the type 145894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman // simplifier to reduce the type, then reuse cast_retty_impl to get the 146894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman // resultant type. 147894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman typedef typename cast_retty<To, SimpleFrom>::ret_type ret_type; 148894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 149894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 150894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate<class To, class FromTy> 151894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumanstruct cast_retty_wrap<To, FromTy, FromTy> { 152894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman // When the simplified type is equal to the from type, use it directly. 153894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman typedef typename cast_retty_impl<To,FromTy>::ret_type ret_type; 154894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 155894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 156894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate<class To, class From> 157894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumanstruct cast_retty { 158894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman typedef typename cast_retty_wrap<To, From, 159894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman typename simplify_type<From>::SimpleType>::ret_type ret_type; 160894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 161894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 162894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// Ensure the non-simple values are converted using the simplify_type template 163894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// that may be specialized by smart pointers... 164894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 165894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate<class To, class From, class SimpleFrom> struct cast_convert_val { 166894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman // This is not a simple type, use the template to simplify it... 167894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman static typename cast_retty<To, From>::ret_type doit(const From &Val) { 168894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman return cast_convert_val<To, SimpleFrom, 169894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman typename simplify_type<SimpleFrom>::SimpleType>::doit( 170894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman simplify_type<From>::getSimplifiedValue(Val)); 171894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 172894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 173894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 174894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate<class To, class FromTy> struct cast_convert_val<To,FromTy,FromTy> { 175894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman // This _is_ a simple type, just cast it. 176894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman static typename cast_retty<To, FromTy>::ret_type doit(const FromTy &Val) { 177894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman typename cast_retty<To, FromTy>::ret_type Res2 178894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman = (typename cast_retty<To, FromTy>::ret_type)const_cast<FromTy&>(Val); 179894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman return Res2; 180894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 181894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 182894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 183894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 184894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 185894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// cast<X> - Return the argument parameter cast to the specified type. This 186894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// casting operator asserts that the type is correct, so it does not return null 18719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// on failure. It does not allow a null argument (use cast_or_null for that). 18819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman// It is typically used like this: 189894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 190894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// cast<Instruction>(myVal)->getParent() 191894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 192894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate <class X, class Y> 193894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumaninline typename cast_retty<X, Y>::ret_type cast(const Y &Val) { 194894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman assert(isa<X>(Val) && "cast<Ty>() argument of incompatible type!"); 195894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman return cast_convert_val<X, Y, 196894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman typename simplify_type<Y>::SimpleType>::doit(Val); 197894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman} 198894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 199894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// cast_or_null<X> - Functionally identical to cast, except that a null value is 200894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// accepted. 201894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 202894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate <class X, class Y> 203894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumaninline typename cast_retty<X, Y*>::ret_type cast_or_null(Y *Val) { 204894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman if (Val == 0) return 0; 205894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman assert(isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!"); 206894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman return cast<X>(Val); 207894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman} 208894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 209894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 210894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// dyn_cast<X> - Return the argument parameter cast to the specified type. This 211894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// casting operator returns null if the argument is of the wrong type, so it can 212894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// be used to test for a type as well as cast if successful. This should be 213894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// used in the context of an if statement like this: 214894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 215894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// if (const Instruction *I = dyn_cast<Instruction>(myVal)) { ... } 216894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 217894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 218894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate <class X, class Y> 219894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumaninline typename cast_retty<X, Y>::ret_type dyn_cast(const Y &Val) { 220894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman return isa<X>(Val) ? cast<X, Y>(Val) : 0; 221894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman} 222894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 223894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// dyn_cast_or_null<X> - Functionally identical to dyn_cast, except that a null 224894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// value is accepted. 225894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 226894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumantemplate <class X, class Y> 22719bac1e08be200c31efd26f0f5fd144c9b3eefd3John Baumaninline typename cast_retty<X, Y*>::ret_type dyn_cast_or_null(Y *Val) { 22819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman return (Val && isa<X>(Val)) ? cast<X>(Val) : 0; 229894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman} 230894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 231894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman} // End llvm namespace 232894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 233894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman#endif 234