https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89611
Bug ID: 89611
Summary: Compilation ok with 'class', but ko with 'struct'
Product: gcc
Version: 8.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: xavier at cremaschi dot fr
Target Milestone: ---
$ g++ --version
g++ (Debian 8.2.0-21) 8.2.0
The following code compiles :
#include <string>
#include <iostream>
#include <variant>
using namespace std;
template<class... Ts> struct Visitor : Ts... {
using Ts::operator()...;
};
template<class... Ts> Visitor(Ts...) -> Visitor<Ts...>;
int main()
{
std::variant<int, string> package;
auto x = Visitor {
[](int) { cout << "int\n"; },
[](string) { cout << "string\n"; },
}
;
std::visit(x, package);
}
But if I replace 'struct Visitor' by a class and add public visibility, it
doesn't :
#include <string>
#include <iostream>
#include <variant>
using namespace std;
template<class... Ts> class Visitor : Ts... {
public:
using Ts::operator()...;
};
template<class... Ts> Visitor(Ts...) -> Visitor<Ts...>;
int main()
{
std::variant<int, string> package;
auto x = Visitor {
[](int) { cout << "int\n"; },
[](string) { cout << "string\n"; },
}
;
std::visit(x, package);
}
AFAIK class or struct is just a matter of default visibility, so I think both
cases should work.
