project2nd<Arg1 Arg2>


Category: functors	Component type: type

Description

Project2nd is a function object that takes two arguments and returns its second argument; the first argument is unused. It is essentially a generalization of identity to the case of a Binary Function.

Example

int main()
{
  vector<char*> v1(10
(char*) 0);
  vector<int> v2(10
137);
  vector<int> result(10);

  transform(v1.begin()
v1.end()
v2.begin()
result.begin()

            project2nd<char*
int>());
  assert(equal(v2.begin()
v2.end()
result.begin()));
}

Definition

Defined in the standard header functional and in the nonstandard backward-compatibility header function.h. This function object is an SGI extension; it is not part of the C++ standard.

Template parameters

Parameter	Description	Default
`Arg1`	`project2nd`'s first argument type.
`Arg2`	`project2nd`'s second argument type and its result type.

Model of

Adaptable Binary Function

Type requirements

None.

Public base classes

binary_function<Arg1 Arg2 Arg2>

Members

Member	Where defined	Description
`first_argument_type`	Adaptable Binary Function	The type of `project2nd`'s first argument: `Arg1`
`second_argument_type`	Adaptable Binary Function	The type of `project2nd`'s second argument: `Arg2`
`result_type`	Adaptable Binary Function	The type of the result: `Arg2`.
`Arg1 operator()(const Arg1& const Arg2& y) const`	Adaptable Binary Function	Function call. The return value is `y`.

New members

All of project2nd's members are defined in the Adaptable Binary Function requirements. project2nd does not introduce any new members.