Global Functions and Macros
| rwtMakeFunctor1() rwtMakeFunctor1G() |
rwtMakeFunctor1GA1() rwtMakeFunctor1GA2() |
rwtMakeFunctor1M() rwtMakeFunctor1MA1() |
rwtMakeFunctor1MA2() |
#include <rw/functor/functor1.h>
A function object, or functor, is an object that encapsulates a call to an associated global or member function. When a functor is invoked, it calls the associated function.
The rwtMakeFunctor1 functions and macros are provided to construct functors based on the RWTFunctor1<S1> class. The RWTFunctor1<S1> class acts as the handle for a family of functor implementation classes based on the RWTFunctor1Imp<S1> class. A functor based on RWTFunctor1<S1> is invoked with one argument and returns no value, but the implementation classes can accept functions with up to two additional arguments and any return type. The values for the additional arguments are defined when an implementation class instance is constructed, and are passed to the function each time the functor is invoked.
Each rwtMakeFunctor1 function or macro instantiates and constructs an appropriate functor implementation class instance and returns an RWTFunctor1<S1> handle that is bound to that instance.
rwtMakeFunctor1 comes in two flavors. First, there is a set of overloaded global function templates. Since not all compilers are able to handle templates to the degree required by these functions, we also provide a corresponding set of macros. The template functions are slightly easier to use and you only have to remember one name. The macros are more portable but they do require more arguments; and because we cannot overload macros, each must have a unique name.
In naming the macros we have employed a convention to make the names easier to remember. Each name begins with rwtMakeFunctor1, which will be followed by either a G if the macro is expecting a global function, or an M if it is expecting a member function. At that point the name is complete if the associated global or member function takes no additional arguments. Otherwise we add one of A1 or A2 for functions with 1 or 2 additional arguments respectively. For example, you will use macro rwtMakeFunctor1G to create a functor that calls a global function that takes no additional arguments. The macro rwtMakeFunctor1MA2 will create a functor that calls a member function that takes two additional arguments.
class A {
public:
int bar(char); // Member function with 1 argument
// (no additional)
};
A a; // an instance of class A
float s;
char c;
int foo(double, long); // Global function with 2 args
// (1 additional)
// Create an RWTFunctor1 set to call foo(s, 11):
RWTFunctor1<float> t1
= rwtMakeFunctor1((void(*)(float))NULL, foo, 11);
// Create an RWTFunctor1 set to call a.bar(c):
RWTFunctor1<char> t2
= rwtMakeFunctor1((void(*)(char))NULL, a, &A::bar);
s = 3.14;
c = 'x';
t1(s); // calls foo(s,11);
t2(c); // calls a.bar(c);
class A {
public:
int bar(char); // Member function with 1 argument
// (no additional)
};
A a; // an instance of class A
float s;
char c;
int foo(double, long); // Global function with 2 args
// (1 additional)
// Create an RWTFunctor1 set to call foo(s, 11):
RWTFunctor1<float> t1
= rwtMakeFunctor1GA1(float, int, foo, double, long, 11);
// Create an RWTFunctor1 set to call a.bar(c):
RWTFunctor1<char> t2
= rwtMakeFunctor1M(char, A, a, int, &A::bar, char);
s = 3.14;
c = 'x';
t1(s); // calls foo(s,11);
t2(c); // calls a.bar(c);
The following information applies to each of the function templates in this section:
s refers to the argument passed when invoking the functor via RWTFunctor1<S1>::operator()(S1). The argument will be passed through to the associated function.
The invokeAs parameter is used only to allow the compiler to deduce type S1. You may use any function with an appropriate signature or simply pass a NULL pointer cast to the appropriate type as done in the example above.
Type S1 must be convertible to D1.
Where applicable, a1 and a2 must be convertible to instances of types A1 and A2 respectively.
template <class S1, class DR, class D1> RWTFunctor1<S1> rwtMakeFunctor1(void (*invokeAs)(S1), DR (*function)(D1));
Creates an RWTFunctor1<S1> set to call function(s).
template <class S1, class DR, class D1, class A1, class AA1>
RWTFunctor1<S1>
rwtMakeFunctor1(void (*invokeAs)(S1),
DR (*function)(D1,A1), AA1 a1)
Creates an RWTFunctor1<S1> set to call function(s,a1).
template <class S1, class DR, class D1, class A1, class A2,
class AA1, class AA2>
RWTFunctor1<S1>
rwtMakeFunctor1(void (*invokeAs)(S1),
DR (*function)(D1,A1,A2), AA1 a1, AA2 a2)
Creates an RWTFunctor1<S1> set to call function(s,a1,a2).
template <class S1, class Callee, class DR, class D1>
RWTFunctor1<S1>
rwtMakeFunctor1(void(*invokeAs)(S1), Callee& callee,
DR (Callee::*function)(D1))
Creates an RWTFunctor1<S1> set to call callee.function(s).
template <class S1, class Callee, class DR, class D1,
class A1, class AA1>
RWTFunctor1<S1>
rwtMakeFunctor1(void(*invokeAs)(S1), Callee& callee,
DR (Callee::*function)(D1,A1), AA1 a1)
Creates an RWTFunctor1<S1> set to call callee.function(s,a1).
template <class S1, class Callee, class DR, class D1,
class A1, class A2, class AA1, class AA2>
RWTFunctor1<S1>
rwtMakeFunctor1(void(*invokeAs)(S1), Callee& callee,
DR (Callee::*function)(D1,A1,A2), AA1 a1, AA2 a2)
Creates an RWTFunctor1<S1> set to call callee.function(s,a1,a2).
The macros in this section use the following naming conventions for the macro arguments:
| S1 | Type name of the first argument that will be expected when invoking the functor via RWTFunctor1<S1>::operator()(S1). S1 must be convertible to D1. |
| DR | Type name of the function return value. |
| function | Global function pointer. |
| D1 | Type name of the first argument of the function |
| A1 | Type name of the first additional argument. |
| a1 | Expression that can be converted to an instance of A1. |
| A2 | Type name of the second additional argument. |
| a2 | Expression that can be converted to an instance of A2. |
| s | Argument of type S1 that will be passed when invoking the functor. |
rwtMakeFunctor1G(S1,DR,function,D1)
Creates an RWTFunctor1<S1> set to call function(s).
function must have signature DR (*)(D1).
rwtMakeFunctor1GA1(S1,DR,function,D1,A1,a1)
Creates an RWTFunctor1<S1> set to call function(s,a1).
function must have signature DR (*)(D1,A1).
rwtMakeFunctor1GA2(S1,DR,function,D1,A1,a1,A2,a2)
Creates an RWTFunctor1<S1> set to call function(s,a1,a2).
function must have signature DR (*)(D1,A1,A2).
The macros in this section use the following naming conventions for the macro arguments:
| S1 | Type name of the first argument that will be expected when invoking the functor via RWTFunctor1<S1>::operator()(S1). S1 must be convertible to D1. |
| Callee | Type name of the function's class. |
| callee | Expression that results in a reference to a Callee instance. |
| DR | Type name of the function return value. |
| function | Pointer to member function of class Callee. |
| D1 | Type name of the first argument of the function |
| A1 | Type name of the first additional argument. |
| a1 | Expression that can be converted to an instance of A1. |
| A2 | Type name of the second additional argument. |
| a2 | Expression that can be converted to an instance of A2. |
| s | Argument of type S1 that will be passed when invoking the functor. |
rwtMakeFunctor1M(S1,Callee,callee,DR,function,D1)
Creates an RWTFunctor1<S1> set to call callee.function(s).
function must have signature DR (Caller::*)(D1).
rwtMakeFunctor1MA1(S1,Callee,callee,DR,function,D1,A1,a1)
Creates an RWTFunctor1<S1> set to call callee.function(s,a1).
function must have signature DR (Caller::*)(D1,A1).
rwtMakeFunctor1MA2(S1,Callee,callee,DR,function,D1,A1,a1,A2,a2)
Creates an RWTFunctor1<S1> set to call callee.function(s,a1,a2).
function must have signature DR (Caller::*)(D1,A1,A2).
RWTFunctor1<S1>, RWTFunctor1Imp<S1>
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