Lifetime of implicitly casted temporaries
- by Answeror
I have seen this question.
It seems that regardless of the cast, the temporary object(s) will "survive" until the fullexpression evaluated.
But in the following scenario:
void foo(boost::tuple<const double&> n) {
printf("%lf\n", n.get<0>());
}
int main() {
foo(boost::tuple<const double&>(2));//#1
foo(boost::make_tuple(2));//#2
return 0;
}
1 run well, but 2 do not.
And MSVC gave me a warning about 2: "reference member is initialized to a temporary that doesn't persist after the constructor exits"
Now I am wondering why they both make a temporary "double" object and pass it to boost::tuple<const double&> and only 2 failed.
