https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90320
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Known to work| |5.5.0
Keywords| |rejects-valid
Last reconfirmed| |2019-05-24
CC| |paolo at gcc dot gnu.org
Ever confirmed|0 |1
Summary|Explicit constructor called |[7/8/9/10 Regression]
|implicitly |Explicit constructor called
| |implicitly
Known to fail| |10.0, 6.5.0, 7.4.0, 8.3.0,
| |9.1.0
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Here's a rejects-valid testcase that Clang and EDG accept:
struct M {
M() = default;
template <typename T> explicit M(T&&) = delete;
};
struct V {
V(M m);
};
M m;
V v = m;
GCC tries to use the deleted constructor template instead of the copy
constructor when initializing the parameter of V::V(M):
m.cc:11:7: error: use of deleted function ‘M::M(T&&) [with T = M&]’
V v = m;
^
m.cc:3:34: note: declared here
template <typename T> explicit M(T&&) = delete;
^
m.cc:7:3: note: initializing argument 1 of ‘V::V(M)’
V(M m);
^
M::M<M&>(M&) is a better match for a non-const lvalue than the implicit
M::M(const M&) copy constructor, but because it's explicit it shouldn't be
used.
GCC 5 compiled it OK (with -std=c++11) but it started to be rejected with
r225705:
PR c++/54521
* call.c (convert_like_real): Do not set LOOKUP_ONLYCONVERTING for
the second step of copy-initialization.
