https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68525
Bug ID: 68525
Summary: bogus use of deleted function error on a template with
a flexible array member
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
Recent trunk gets confused by the program below into issuing a rather
mysterious error. Both Clang and Gcc 5.1 compile the code without an error.
$ cat z.cpp && /build/gcc-trunk-svn/gcc/xgcc -B /build/gcc-trunk-svn/gcc -Wall
-Wextra -Wpedantic -O2 -S -o/dev/tty -xc++ z.cpp
template <class T>
struct A {
int n;
T a[];
};
struct B { B (int); };
A<B> ab;
.file "z.cpp"
z.cpp:4:9: warning: ISO C++ forbids zero-size array ‘a’ [-Wpedantic]
T a[];
^
z.cpp:9:6: error: use of deleted function ‘A<B>::A()’
A<B> ab;
^~
z.cpp:2:8: note: ‘A<B>::A()’ is implicitly deleted because the default
definition would be ill-formed:
struct A {
^
z.cpp:2:8: error: no matching function for call to ‘B::B()’
z.cpp:7:12: note: candidate: B::B(int)
struct B { B (int); };
^
z.cpp:7:12: note: candidate expects 1 argument, 0 provided
z.cpp:7:8: note: candidate: constexpr B::B(const B&)
struct B { B (int); };
^
z.cpp:7:8: note: candidate expects 1 argument, 0 provided
z.cpp:7:8: note: candidate: constexpr B::B(B&&)
z.cpp:7:8: note: candidate expects 1 argument, 0 provided
