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PR9546, DR1268: A prvalue cannot be reinterpret_cast to an rvalue reference 

type. But a glvalue can be reinterpret_cast to either flavor of reference.

llvm-svn: 155789
This commit is contained in:
Richard Smith 2012-04-29 08:24:44 +00:00
parent 4f402bd985
commit db05f1fb08
2 changed files with 8 additions and 6 deletions
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7
clang/lib/Sema/SemaCast.cpp
View File

@ -1504,10 +1504,9 @@ static TryCastResult TryReinterpretCast(Sema &Self, ExprResult &SrcExpr,
}
if (const ReferenceType *DestTypeTmp = DestType->getAs<ReferenceType>()) {
bool LValue = DestTypeTmp->isLValueReferenceType();
if (LValue && !SrcExpr.get()->isLValue()) {
// Cannot cast non-lvalue to lvalue reference type. See the similar
// comment in const_cast.
if (!SrcExpr.get()->isGLValue()) {
// Cannot cast non-glvalue to (lvalue or rvalue) reference type. See the
// similar comment in const_cast.
msg = diag::err_bad_cxx_cast_rvalue;
return TC_NotApplicable;
}

7
clang/test/CXX/expr/expr.post/expr.reinterpret.cast/p1-0x.cpp
View File

@ -10,7 +10,10 @@ template<typename T> T&& xvalue();
void test_classification(char *ptr) {
int (&fr0)(int) = reinterpret_cast<int (&&)(int)>(f);
int &&ir0 = reinterpret_cast<int &&>(*ptr);
int &&ir1 = reinterpret_cast<int &&>(0);
int &&ir2 = reinterpret_cast<int &&>('a');
int &&ir1 = reinterpret_cast<int &&>(0); // expected-error {{rvalue to reference type}}
int &&ir2 = reinterpret_cast<int &&>('a'); // expected-error {{rvalue to reference type}}
int &&ir3 = reinterpret_cast<int &&>(xvalue<char>());
// Per DR1268, reinterpret_cast can convert between lvalues and xvalues.
int &ir4 = reinterpret_cast<int &>(xvalue<char>());
int &&ir5 = reinterpret_cast<int &&>(*ptr);
}