from: https://www.facebook.com/groups/cppjp/permalink/457399574360991/

hoge.cpp

#include <iostream>
#include <typeinfo>

struct Hoge {
  int a;
};

void f(Hoge& hoge);

void g() {
  Hoge h = { -1 };
  f(h);
  std::cerr << typeid(h).name() << " " << sizeof(h)<< "\n";
}

main.cpp

#include <iostream>
#include <typeinfo>

struct Hoge {
int c;
int a;
};

void g();

void f(Hoge& hoge) {
  std::cerr << typeid(hoge).name() << " " << sizeof(hoge) << "\n";
}

int main() {
  Hoge h = { 0, 1 };
  f(h);
  g();
}

[result: compile & run]

uname -a
Linux LH-MAIN 3.8.0-34-generic #49-Ubuntu SMP Tue Nov 12 18:00:10 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
{ clang++-3.2.1 | g++-4.7.3 } -O0 -g -o hoge -Wall -pedantic-errors hoge.cpp main.cpp
./hoge
4Hoge 8
4Hoge 8
4Hoge 8