//测试c++中结构体的字节对齐#include <iostream>#include <cmath>using namespace std;void vsVersion();//example 1struct Node1{ char a; int b; double c;};//example 2struct Node2 { char a; int b; char c;};//example 3struct Node3{};//example 4struct Node4{ char a; int b; static double c;};//example 5struct Inside { int a; double b; float c;};struct Node5 { char e[2]; int f; short h; struct Inside inside;};//example 6struct Node6 { char a; int b; float c; double d; int* p; char* pc; short e;};int main(){ Node1 n1; Node2 n2; Node3 n3; Node4 n4; Node5 n5; Node6 n6; vsVersion();//宏定义:https://docs.microsoft.com/en-us/cpp/preprocessor/predefined-macros?redirectedfrom=MSDN&view=vs-2019#ifdef _WIN64 cout << "--------x64----------------" << endl; cout << "char:" << sizeof(char) << endl; cout << "short:" << sizeof(short) << endl; cout << "int:" << sizeof(int) << endl; cout << "double:" << sizeof(double) << endl; cout << "float:" << sizeof(float) << endl; cout << "char *:" << sizeof(char *) << endl; cout << "Node1 :" << sizeof(n1) << endl; cout << "Node2 :" << sizeof(n2) << endl; cout << "Node3 :" << sizeof(n3) << endl; cout << "Node4 :" << sizeof(n4) << endl; cout << "Node5 :" << sizeof(n5) << endl; cout << "Node6 :" << sizeof(n6) << endl;#else cout << "--------x86----------------" << endl; cout << "char:" << sizeof(char) << endl; cout << "short:" << sizeof(short) << endl; cout << "int:" << sizeof(int) << endl; cout << "double:" << sizeof(double) << endl; cout << "float:" << sizeof(float) << endl; cout << "char *:" << sizeof(char*) << endl; cout << "Node1 :" << sizeof(n1) << endl; cout << "Node2 :" << sizeof(n2) << endl; cout << "Node3 :" << sizeof(n3) << endl; cout << "Node4 :" << sizeof(n4) << endl; cout << "Node5 :" << sizeof(n5) << endl; cout << "Node6 :" << sizeof(n6) << endl;#endif cout << "hello world" << endl; return 0;}//确定IDE版本void vsVersion(){ if (_MSC_VER == 1921 or _MSC_VER == 1922 or _MSC_VER == 1923) { cout << "vs2019" << endl; } else if (_MSC_VER == 1910 or _MSC_VER == 1911 or _MSC_VER == 1912 or _MSC_VER == 1913 or _MSC_VER == 1914 or _MSC_VER == 1915 or _MSC_VER == 1916) { cout << "vs2017" << endl; } else { cout << "others" << endl; }}