Passing function parameter and static

[Banjiji]

#include <string>
#include <iostream>
using namespace std;
struct Functor{
bool operator()(const std::string& str){cout<<str<<endl;return true;}
};
struct Functor2{
static bool compute(const std::string& str){cout<<str<<endl;return true;}
};
struct Foo
{
template<class F>
void callMe()
{
 F()("operator ()");
}
template<class F>
void callMe2()
{
 F::compute("static");
}
};
int main(int n,char ** arfv)
{
Foo obj;
obj.callMe<Functor>();
obj.callMe2<Functor2>();
system("pause");
}

If you want to pass a function parameter which method is better to use: functor or functor2?

[Zecho]

What is static over here? Static method means a state where the compiler does not allow any reentry. That means, you cannot change anything in that method or variable. In short, none of the two is recommended. The idiom favored by the standard:

template<class Fun> void callMe( Func f)
{
f("operator ()" );
}

[Banjiji]

I recently read a language such as ADA which is assumed to be better than C++ programming for parallel/concurrent. And with the next version of C++ or the development of third-lib, we can not hope that one day the C++ is doing better in this area? Any comments?

[kelfro]

#include <string>
#include <iostream>
using namespace std;
struct Functor{
bool operator()(const std::string& str){cout<<str<<endl;return true;}
};
struct Functor2{
static bool compute(const std::string& str){cout<<str<<endl;return true;}
};
struct Foo
{
template<class F>
void callMe()
{
 F()("operator ()");
}
template<class F>
void callMe2()
{
 F::compute("static");
}
};
int main(int n,char ** arfv)
{
Foo obj;
obj.callMe<Functor>();
obj.callMe2<Functor2>();
system("pause");
}

If you want to pass a function parameter which method is better to use: functor or functor2?

do not use static data (unless they are constants), using only data from the caller, do not call next function

Regarding ADA:

Ada is a structured, statically typed, imperative, wide-spectrum, and object-oriented high-level computer programming language, extended from Pascal and other languages. Ada is strongly typed and compilers are validated for reliability in mission-critical applications, such as avionics software.