bslmf_functionpointertraits

Detailed Description

Provide a meta-function for determining function pointer traits.

Outline

• Purpose
• Classes
• Description
  • Usage

Purpose

Provide a meta-function for determining function pointer traits.

Classes

• bslmf::FunctionPointerTraits: meta-function for detecting function pointer
• traits
• bslmf::IsFunctionPointer: meta-function to determine if a type is a
• function pointer

See also

bslmf_memberfunctionpointertraits

Description

This component provides meta-functions for determining whether a type is a pointer to either a free function or a class method (but not to a member function, see the component bslmf_memberfunctionpointertraits component for that), and some information about this function type. The meta-function bslmf::IsFunctionPointer provides an enumerated value which can be either 1 or 0 depending on whether or not the template argument t_PROTOTYPE is a pointer to a free function or class method. In the affirmative, the class bslmf::FunctionPointerTraits also provides information regarding the function type, such as its argument list type and its return type.

Note that there is no reference-to-function traits class, since whether FUNC is a reference to function type can be very easily obtained using the meta-function call bslmf::IsFunctionPointer<FUNC *>.

Usage

Define the following function types:

typedef int  (*IntFunctionIntIntPtr)(int, int);
typedef void (*VoidFunc0)();

The following program should compile and run without errors:

int main()
{
    assert(0 == bslmf::IsFunctionPointer<int>::value);
    assert(0 == bslmf::IsFunctionPointer<void>::value);
 
    assert(1 == bslmf::IsFunctionPointer<IntFunctionIntIntPtr>::value);
    typedef bslmf::FunctionPointerTraits<IntFunctionIntIntPtr>::ResultType
        ResultType1;
    assert(1 == (bsl::is_same<ResultType1, int>::value));
 
    assert(1 == bslmf::IsFunctionPointer<VoidFunc0>::value);
    typedef bslmf::FunctionPointerTraits<VoidFunc0>::ResultType
        ResultType0;
    typedef bslmf::FunctionPointerTraits<VoidFunc0>::ArgumentList
        ArgList0;
    assert(1 == (bsl::is_same<ResultType0, void>::value));
    assert(1 == (bsl::is_same<ArgList0, bslmf::TypeList0>::value));
}

Typedefs
typedef bslmf::FunctionPointerCPlusPlusLinkage	bslmf_FunctionPointerCPlusPlusLinkage
typedef bslmf::FunctionPointerCLinkage	bslmf_FunctionPointerCLinkage

Macro Definition Documentation

bslmf_FunctionPointerTraits

#define bslmf_FunctionPointerTraits   bslmf::FunctionPointerTraits

This alias is defined for backward compatibility.

bslmf_IsFunctionPointer

#define bslmf_IsFunctionPointer   bslmf::IsFunctionPointer

This alias is defined for backward compatibility.

Typedef Documentation

bslmf_FunctionPointerCLinkage

typedef bslmf::FunctionPointerCLinkage bslmf_FunctionPointerCLinkage

This alias is defined for backward compatibility.

bslmf_FunctionPointerCPlusPlusLinkage

typedef bslmf::FunctionPointerCPlusPlusLinkage bslmf_FunctionPointerCPlusPlusLinkage

This alias is defined for backward compatibility.