void형 변수 선언이 가능?

순수 가상 함수'로 비슷한 효과를 볼 수 있습니다.
http://blog.naver.com/cyber13510/220590497806
http://yoon90.tistory.com/8
 
#define ## 매크로.등을 사용해서. 비슷한 효과를 볼 수 있습니다.

#include <stdio.h>
 
int main()
{
	void a;
	printf("%d\n", sizeof(a));
 
    return 0;
}
 
Severity	Code	Description	Project	File	Line	Suppression State
Error	C2182	'a': illegal use of type 'void'	ConsoleApplication1	c:\users\ieuser\desktop\consoleapplication1\consoleapplication1.cpp	12	

#include <stdio.h>
 
int main()
{
 
	void * b;
	printf("%d\n", sizeof(b));
    return 0;
}
 
x86 은 4바이트
x64 는 8바이트

근데. 리턴값으로 void 형은 가능하죠. ㅇ_ㅇ;;
void fn()
{
	return;
}

#include <stdio.h>
 
template <typename T>
class Template
{
public:
	T a, b;
	Template()
	{
		printf("constructor\n");
	}
};
 
 
void main()
{
	Template<void> test1;
}
 
Severity	Code	Description	Project	File	Line	Suppression State
Error	C2182	'a': illegal use of type 'void'	ConsoleApplication1	c:\users\ieuser\desktop\consoleapplication1\consoleapplication1.cpp	25	
 
http://changmyeong.tistory.com/9

#include <queue>
 
using namespace std;
 
int main()
{
	queue<void> a;
    return 0;
}
 
Severity	Code	Description	Project	File	Line	Suppression State
Error	C2182	'abstract declarator': illegal use of type 'void'	ConsoleApplication1	c : \program files(x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.10.24728\include\xmemory0	163
Error	C2182	'abstract declarator': illegal use of type 'void'	ConsoleApplication1	c : \program files(x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.10.24728\include\xmemory0	165
Error	C2182	'reference': illegal use of type 'void'	ConsoleApplication1	c : \program files(x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.10.24728\include\deque	978
Error	C2182	'const_reference': illegal use of type 'void'	ConsoleApplication1	c : \program files(x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.10.24728\include\deque	979
Error	C2070	'void': illegal sizeof operand	ConsoleApplication1	c : \program files(x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.10.24728\include\deque	986
Error	C2182	'_Val': illegal use of type 'void'	ConsoleApplication1	c : \program files(x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.10.24728\include\deque	1003

#include <iostream>
 
using namespace std;
 
template<bool B, class T = void>
struct enable_if {};
 
 
class Foo {
public:
	template <typename... Args, class T = void>
	Foo(Args... args) {
		cout << "Foo::Foo(args...)" << endl;
	}
};
 
 
int main()
{
 
	return 0;
}
이 방식은 컴파일이 가능하네요.