https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83205
Bug ID: 83205
Summary: ICE on structured binding with ill-formed negative
std::tuple_size<T>::value
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: jcemmett1 at gmail dot com
Target Milestone: ---
The following ill-formed code results in an ICE with GCC 8. Needs only
-std=c++17.
=====
struct Foo { int i; };
namespace std {
template <typename T> struct tuple_size;
template <> struct tuple_size<Foo> {
static constexpr int value = -1;
};
}
int main()
{
auto [i] = Foo{};
}
=====
Output:
GNU C++17 (GCC-Explorer-Build) version 8.0.0 20171128 (experimental)
(x86_64-linux-gnu)
compiled by GNU C version 5.4.0 20160609, GMP version 6.1.0, MPFR
version 3.1.4, MPC version 1.0.3, isl version isl-0.18-GMP
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
Compiler executable checksum: 6355e9ef8f7b704fe373fdf166e4fd6e
<source>: In function 'int main()':
14 : <source>:14:20: internal compiler error: in tree_to_uhwi, at tree.c:6643
auto [i] = Foo{};
^
mmap: Cannot allocate memory
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://gcc.gnu.org/bugs/> for instructions.
Compiler exited with result code 1
Godbolt link: https://godbolt.org/g/NJ6fLG
