https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91742
--- Comment #8 from Diego Franco <di...@franco-technologies.com> ---
So to summarize, these are the main reason why I believe this should be
addressed:
- init brace works for references of any type:
std::vector<int> a {};
std::vector<int>& b {a};
assert(&a == &b); // works
int c {};
int& d {c};
assert(&c == &d); // works
- init brace works for user defined conversion reference when using static
cast:
class A {
operator const std::vector<int>&() const {return a_;}
std::vector<int> a_;
};
A a {};
const auto& b {static_cast<const std::vector<int>&>(a)};
assert(&a == &b); // works
- init brace does not work for user defined conversion reference WITHOUT static
cast:
A a {};
const auto& b {a};
assert(&a == &b); // does not work
I think the above behavior is quite unexpected, and does not follow any logic
of other behaviors in the language. I found this unexpected behavior by running
unit tests. Also, semantic wise is correct to use user-defined-conversion
without static cast (above example).
