forked from OSchip/llvm-project
Modifications to dyn_cast/cast to make them work for objects too, instead of only pointers.
The use case is if you have a wrapper class: class Base { void *Ptr; public: Base() : Ptr(0) { } operator bool() const { return Ptr; } ..... } and sub-wrappers that have exactly the same size: class Sub : public Base { public: .... static bool classof(const Base*); } and in the code you would do: void f(Base b) { Sub sub = dyn_cast<Sub>(b); if (sub) { .... } } llvm-svn: 78424
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@ -205,8 +205,9 @@ inline typename cast_retty<X, Y>::ret_type cast(const Y &Val) {
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// accepted.
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//
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template <class X, class Y>
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inline typename cast_retty<X, Y*>::ret_type cast_or_null(Y *Val) {
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if (Val == 0) return 0;
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inline typename cast_retty<X, Y>::ret_type cast_or_null(const Y &Val) {
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typedef typename cast_retty<X, Y>::ret_type ret_type;
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if (!Val) return ret_type();
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assert(isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!");
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return cast<X>(Val);
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}
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@ -222,7 +223,8 @@ inline typename cast_retty<X, Y*>::ret_type cast_or_null(Y *Val) {
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template <class X, class Y>
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inline typename cast_retty<X, Y>::ret_type dyn_cast(const Y &Val) {
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return isa<X>(Val) ? cast<X, Y>(Val) : 0;
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typedef typename cast_retty<X, Y>::ret_type ret_type;
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return isa<X>(Val) ? cast<X, Y>(Val) : (ret_type)ret_type();
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}
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// dyn_cast_or_null<X> - Functionally identical to dyn_cast, except that a null
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@ -230,7 +232,8 @@ inline typename cast_retty<X, Y>::ret_type dyn_cast(const Y &Val) {
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//
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template <class X, class Y>
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inline typename cast_retty<X, Y>::ret_type dyn_cast_or_null(const Y &Val) {
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return (Val && isa<X>(Val)) ? cast<X, Y>(Val) : 0;
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typedef typename cast_retty<X, Y>::ret_type ret_type;
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return (Val && isa<X>(Val)) ? cast<X, Y>(Val) : (ret_type)ret_type();
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}
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