CppTest/Cpp/Class/EmptyStructSizeOf.cpp at master · skynowa/CppTest · GitHub

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/**
 * \file  EmptyStructSizeOf.cpp
 * \brief
 */


#include <StdStream/StdStream.h>
#include <StdTest/StdTest.h>

//-------------------------------------------------------------------------------------------------
struct A_1byte
{
};
//-------------------------------------------------------------------------------------------------
struct B_1byte :
	A_1byte
{
};
//-------------------------------------------------------------------------------------------------
// error: ISO C++ forbids zero-size array ‘NO_DATA’ [-Werror=pedantic]
#if 0

class C_0byte
{
	int NO_DATA[0];
};

#endif
//-------------------------------------------------------------------------------------------------
class D_1byte
{
	int foo() { return 0; }
};
//-------------------------------------------------------------------------------------------------
class D_8byte
{
	virtual int foo() { return 0; }
};
//-------------------------------------------------------------------------------------------------
class E_4byte
{
	int value;
};
//-------------------------------------------------------------------------------------------------
class F_16byte
{
	D_8byte value1;
	E_4byte value2;
};
//-------------------------------------------------------------------------------------------------
int main(int, char **)
{
	std::cout
		<< STD_TRACE_VAR(sizeof(A_1byte))  << "\n"
		<< STD_TRACE_VAR(sizeof(B_1byte))  << "\n"
		// << STD_TRACE_VAR(sizeof(C_0byte))  << "\n"
		<< STD_TRACE_VAR(sizeof(D_1byte))  << "\n"
		<< STD_TRACE_VAR(sizeof(D_8byte))  << "\n"
		<< STD_TRACE_VAR(sizeof(E_4byte))  << "\n"
		<< STD_TRACE_VAR(sizeof(F_16byte)) << "\n"
		<< std::endl;

	return 0;
}
//-------------------------------------------------------------------------------------------------


#if OUTPUT

sizeof(A_1byte): 1
sizeof(B_1byte): 1
sizeof(C_0byte): 0
sizeof(D_1byte): 1
sizeof(D_8byte): 8
sizeof(E_4byte): 4
sizeof(F_16byte): 16

#endif