https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103295
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The code can be reduced to this, which GCC, EDG and MSVC all accept, but Clang
doesn't:
struct S
{
union {
char buf[8];
char* ptr;
};
unsigned len;
constexpr S(const char* s, unsigned n)
{
char* p;
if (n > 7)
p = ptr = new char[n];
else
p = buf;
for (len = 0; len < n; ++len)
p[len] = s[len];
p[len] = '\0';
}
constexpr ~S()
{
if (len > 7)
delete[] ptr;
}
};
constexpr bool test()
{
S s("test", 4);
return true;
}
static_assert( test() );
Clang accepts it if written like this:
constexpr S(const char* s, unsigned n)
{
if (n > max_size())
{
ptr = new char[n];
for (len = 0; len < n; ++len)
ptr[len] = s[len];
ptr[len] = '\0';
}
else
{
for (len = 0; len < n; ++len)
buf[len] = s[len];
buf[len] = '\0';
}
}
It just doesn't allow assignment through the pointer.
