[Bug c++/52282] [C++0x] ICE / confused by earlier errors with decltype/constexpr

[andyg1001 at hotmail dot co.uk]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52282

--- Comment #3 from andyg1001 at hotmail dot co.uk 2012-05-04 16:22:21 UTC ---
This ICE still occurs in the release version of gcc 4.7.0.

Here is the output from compiling the attached test-case as is:

$ g++-4.7 -std=c++11 ice.cpp
ice.cpp: In instantiation of ‘struct Z<const int*, (& a)>’:
ice.cpp:39:33:   required from here
ice.cpp:11:41: internal compiler error: in finish_decltype_type, at
cp/semantics.c:5277
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.7/README.Bugs> for instructions.
Preprocessed source stored into /tmp/ccPyRnUB.out file, please attach this to
your bugreport.

And if the lines in the test-case marked "ICE" are commented out, then this is
the output:

$ g++-4.7 -std=c++11 ice.cpp
ice.cpp:47:1: error: non-constant condition for static assertion
ice.cpp:47:43: error: expression ‘b<10>’ does not designate a constexpr
function
ice.cpp:48:1: error: non-constant condition for static assertion
ice.cpp:48:43: error: expression ‘b<10>’ does not designate a constexpr
function
ice.cpp:64:1: error: non-constant condition for static assertion
ice.cpp:64:56: error: expression ‘0u’ does not designate a constexpr function
ice.cpp:65:1: error: non-constant condition for static assertion
ice.cpp:65:56: error: expression ‘0u’ does not designate a constexpr function
ice.cpp:66:1: error: non-constant condition for static assertion
ice.cpp:66:56: error: expression ‘0u’ does not designate a constexpr function
ice.cpp:67:1: error: non-constant condition for static assertion
ice.cpp:67:56: error: expression ‘0u’ does not designate a constexpr function
ice.cpp:70:1: error: non-constant condition for static assertion
ice.cpp:70:43: error: expression ‘C::c2’ does not designate a constexpr
function
ice.cpp:71:1: error: non-constant condition for static assertion
ice.cpp:71:43: error: expression ‘C::c2’ does not designate a constexpr
function

The attached test-case compiles and runs successfully under clang with one
small change as shown in this diff (this doesn't affect the test-case under
gcc):

--- ice.cpp
+++ ice.cpp
@@ -53,6 +53,7 @@
 static_assert(Z_<int(*)(), &b<10>>::value() == 10, "oops");    // ICE

 constexpr struct C {
+    constexpr C() = default;
     constexpr int c1() const { return 10; }
     static constexpr int c2() { return 10; }
 } c;