I am wondering if there is a way to reuse the call to the function template_fun
in the following c++ code.
#include <iostream>
#include <cstdlib>
#include <ctime>
template <typename T>
double template_fun(T arg)
{
double a = 1.1;
a += (double)arg;
return a;
}
int main()
{
std::srand(std::time(0));
int r = std::rand() % 2;
double out;
switch(r)
{
case 0:
{
int arg = 1;
out = template_fun(arg);
break;
}
case 1:
{
double arg = 1.2;
out = template_fun(arg);
break;
}
}
std::cout << out << "\n";
}
Since the line out = template_fun(arg);
is repeated, I was hoping there was a way to reuse it somehow. Obviously, this issue of calling a template function with different input data types depending on an input is really what I'm getting at. The code I'm working on is much more complex. I am not particularly hopeful for a clever solution, since it would probably mean defining the data type of arg
at runtime. But perhaps I am missing something.
Thank you in advance for your help! Much appreciated.
You may use some variant
class, and do something like:
struct template_fun : boost::static_visitor<double>
{
template <typename T>
double operator() (T arg) const
{
double a = 1.1;
a += (double)arg;
return a;
}
};
int main()
{
std::srand(std::time(0));
int r = std::rand() % 2;
boost::variant<int, double> arg;
double out = 0.0;
switch(r)
{
case 0: { arg = 1; break; }
case 1: { arg = 1.2; break; }
}
out = boost::apply_visitor(template_fun{}, arg);
std::cout << out << "\n";
}
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.