Hello,
The following code compiles and runs correctly but gives a warning:
----------------------------------------
#include<iostream>
using namespace std;
template<class T>
T sum(T value) {
return value;
}
template<class T, class ... U>
auto sum(T value, U ... values) {
return value + sum(values ...);
}
int main() {
cout << sum(1, 2, 4.6) << endl;
cout << sum(1, "abcde", 2) << endl;
}
--------------------------------------
$ g++ -std=c++11 pack.cpp
pack.cpp:11:31: warning: â??sumâ?? function uses
â??autoâ?? type specifier without trailing return type [enabled by default]
auto sum(T value, U ... values) {
$ ./a.exe
7.6
de
-------------------------------------------
All of my attempts to use a trailing return type
failed (and I believe should have failed according to the standard).
My two questions:
1. What possible user mistake is the warning worried about?
2. How can I write my code with better style so that there is no warning?
Thank you.
--Sidney Marshall
