http://llvm.org/bugs/show_bug.cgi?id=16377
Bug ID: 16377
Summary: statement expressions do not evaluate as constexpr
Product: clang
Version: trunk
Hardware: PC
OS: Linux
Status: NEW
Severity: normal
Priority: P
Component: C++11
Assignee: [email protected]
Reporter: [email protected]
CC: [email protected], [email protected]
Classification: Unclassified
The statement expressions extension under gcc permits its use in a constexpr
evaluation. So the following "dummy" code is accepted by gcc:
struct A { };
static_assert(({ 1; }), "oops");
constexpr auto a = ({ A(); });
And this macro which produces a useful diagnostic if used with a non-array
argument also works under gcc:
#define ARRAY_SIZEOF(A) \
({ static_assert(std::extent<__typeof__(A)>::value >= 0, \
TO_STRING(A) " is not an array with size >= 0"); \
std::extent<__typeof__(A)>::value; })
[[The TO_STRING macro isn't given, but it should be fairly clear what it
does!]]
clang unfortunately does not accept any of this code, complaining that it
doesn't constitute a constant expression. Would it be possible to extend clang
to support this?
Thanks.
--
You are receiving this mail because:
You are on the CC list for the bug.
_______________________________________________
LLVMbugs mailing list
[email protected]
http://lists.cs.uiuc.edu/mailman/listinfo/llvmbugs
