[cfe-dev] Small C++ query

[Keno Fischer]

Hi folks,

I'm confused by the following code snippet:

#include <memory>
void foo(int *x) { std::unique_ptr<int>(x); }

both clang and gcc warn that this redefines x, but I don't understand why
this
is a declaration of x. I guess I would have expected a temporary unique_ptr
that gets destructed immediately or an error. How come this actually
defines a variable called x?

To give some background about where this came up, a user wanted to do
C++> std::unique_ptr<int>(x);
in my Clang-based interactive C++ REPL. Behind the scenes this gets
transformed into the function above and then I try to insert a return
statement on the last statement in the body to automatically grab the
result. This works well in most cases but failed here because Clang thinks
this is a variable declaration, so I'd like to understand why this is
happening.

Keno
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-dev/attachments/20150525/14a60524/attachment.html>