icpc (ICC) 19.0.0.117 20180804
This works in g++ but not icpc with the same runtime library includes.
icpc -std=c++17 -c /tmp/t.cpp -o /tmp/t.o
#include <variant>
void foo();
void foo()
{
std::variant<std::monostate, int> bar;
}
Gives:
/tmp/t.cpp(7): error: the default constructor of "std::variant<std::monostate, int>" cannot be referenced -- it is a deleted function
std::variant<std::monostate, int> bar;
According to cppreference, the default constructor "Constructs a variant holding the
value-initialized value of the first alternative (index() is zero). This constructor
is constexpr if and only if the value initialization of the alternative type T_0 would
satisfy the requirements for a constexpr function. This overload only participates in
overload resolution if std::is_default_constructible_v<T_0> is true."↧
Default constructor of variant is deleted ?
↧