member function pointers for the c++--class and Mem_fun adapters

There is such a class that we base on this class:

1 classFoo2 {3  Public:4 5     //void (Foo::*) (int)6     voidFoointa)7     {8cout << a <<Endl;9     }Ten  One     //Void (*) (int) A     Static voidBarinta) -     { -cout << a <<Endl; the     } -};

We try to invoke the function pointer:

void (*pfunc) (int) = &Foo::foo;

Get compile Error:

Error:cannot convert 'void (Foo::*) (int) ' to 'void (*) (int in Initialization

The reason is simple, the class member function, which contains an implicit parameter, this, so the function void foo (int a) contains two parameters.
We should use the Void (Foo::*) (int) type to generate a function pointer using the following method:

void (Foo::* pFunc2) (int) = &Foo::foo; Foo F; (f. *PFUNC2) (*p = &F; (P->*pfunc2);

As opposed to the static member function, we can use it just like a normal function pointer, because the static member function does not have an implicit parameter of this.

We can call the function pointer by doing this:

void (*PFUNC3) (int) = &foo::bar;pfunc3 (N);

in function foo (), it contains an implicit parameter this, so how do we convert it?

We can do this by using Mem_fun in the STL, which is a function adapter.

The calling method is as follows:

Foo F; (Mem_fun);

The way the Mem_fun is transformed is this:

void (Foo::*) (int)  ,   voidint);

member function pointers for the c++--class and Mem_fun adapters