Compiling with msvc failed but with gcc succeeded.

[VirgilMa]

code is here.

class Val : public mpark::variant<bool, int, double, std::string, void*> {
public:
    using mpark::variant<bool, int, double, std::string, void*>::variant;
};

int main() {
    Val val;
    val = true;
    return 0;
}

Thank you so much for your time.