Is there any way to pass a lambda to a function template which takes a std::function<void(T)> argument, and have the T template parameter deduced from the argument of the lambda, rather than having to explicitly state it?
That is, given a lambda of the form [](std::string){...}, deduce T is std::string?
Example:
So with a function template
template<typename T>
void func(std::function<void(T)> f) { ... }
I can call func by explicitly specifying std::string as follows:
func<std::string>([](std::string){...});
I would like to deduce std::string, and call func as follows:
func([](std::string){...});
Examplar app below:
#include <iostream>
#include <functional>
template<typename T>
void func(std::function<void(const T&)> f)
{
T m = "hello world";
f(m);
}
struct foo
{
void bar(std::string msg)
{
std::cout << __func__ << ": " << msg << std::endl;
}
};
int main()
{
foo f;
// explicit specification works
func<std::string>([&](const std::string& m) {
f.bar(m);
});
// relying on argument deduction fails
// func([&](const std::string& m) {
// f.bar(m);
// });
return 0;
}
