[cfe-commits] r162768 - in /cfe/trunk: include/clang/AST/Stmt.h lib/AST/Stmt.cpp

[Jordan Rose]

On Aug 28, 2012, at 11:08 , John McCall <rjmccall at apple.com> wrote:

> On Aug 28, 2012, at 11:05 AM, Chad Rosier wrote:
>> On Aug 28, 2012, at 10:48 AM, Dmitri Gribenko wrote:
>>> On Tue, Aug 28, 2012 at 10:43 AM, Chad Rosier <mcrosier at apple.com> wrote:
>>>> +std::string AsmStmt::generateAsmString(ASTContext &C) const {
>>>> +  StmtClass stmtClass = getStmtClass();
>>>> +  if (stmtClass == Stmt::GCCAsmStmtClass)
>>>> +    return static_cast<const GCCAsmStmt*>(this)->generateAsmString(C);
>>>> +  if (stmtClass == Stmt::MSAsmStmtClass)
>>>> +    return static_cast<const MSAsmStmt*>(this)->generateAsmString(C);
>>>> +  llvm_unreachable("unknown asm statement kind!");
>>>> +}
>>> 
>>> It is conventional to use cast<> in such cases.
>> 
>> I based these changes off of John's work in r125183.  I don't claim to be an expert on the use of casts, but I'm guessing John used the static_cast to elide the run-time checks.  John, please correct me if I'm wrong…
> 
> I don't remember, but it's a bit different in macro-metaprogrammed code.  Here you might as well use cast<>.

Actually, this makes sense for dyn_cast<>…or a switch statement with cast<>.