source: doc/theses/jiada_liang_MMath/test.cc@ d7cb0f7

#include <iostream>
#include <cstdlib>
#include <variant>
using namespace std;

// struct S { char s[32]; };
// variant< int, double, S > vd;
// variant< int, int, int > vs;

// int main() {
//      cout << "sizeof vd " << sizeof( vd ) << endl;
//      vd = 3;
//      if ( holds_alternative<int>(vd) ) cout << "int " << get<int>(vd ) << endl;
//      vd = 3.5;
//      if ( holds_alternative<double>(vd) ) cout << "double " << get<double>(vd) << endl;
//      vd = (S){ "abc" };
//      if ( holds_alternative<S>(vd) ) cout << "S.s " << get<S>(vd).s << endl;

//      cout << "sizeof vs " << sizeof( vs ) << endl;
//      vs = (variant<int,int,int>){ in_place_index<0>, 12 };
//      if ( vs.index() == 0 ) cout << "posn 0 " << get<0>(vs) << endl;
//      vs = (variant<int,int,int>){ in_place_index<1>, 4 };
//      if ( vs.index() == 1 ) cout << "posn 1 " << get<1>(vs) << endl;
//      vs = (variant<int,int,int>){ in_place_index<2>, 5 };
//      if ( vs.index() == 2 ) cout << "posn 2 " << get<2>(vs) << endl;
// }

constexpr auto one = 0 + 1;
const auto NUL = nullptr;
const auto PI = 3.14159;
const auto Plus = '+';
const auto Fred = "Fred";
const auto Mon = 0, Tue = Mon + 1, Wed = Tue + 1, Thu = Wed + 1, Fri = Thu + 1, Sat = Fri + 1, Sun = Sat + 1;
const auto r = random();

enum E { A, B, C };
enum class EC : long { A, B, C };

int a1[Sun + 1], a2[C + 1];

int main() {
        const auto one = random();
//      const int * ip = &one;
        int sa[Sun];
        int * i = NUL;
        E e;
        // switch ( e ) {
        //   case w: ;
        // }
        switch ( e ) {
          case Sat: ;
        }
        switch ( e ) {
          case C: ;
        }
        EC ec;
        switch ( ec ) {
          case EC::A: ;
        }
        EC eca[C];
        eca[A] = EC::A;

        enum Week { Mon, Tue, Wed, Thu = 10, Fri, Sat, Sun };
        Week day = Mon;
        if ( day <= Fri ) cout << "weekday" << endl;
        switch ( day ) {
          case Mon: case Tue: case Wed: case Thu: case Fri:
                cout << "weekday" << endl; break;
          case Sat: case Sun:
                cout << "weekend" << endl; break;
        }
        for ( Week d = Mon; d <= Sun; d = (Week)(d + 1) ) {
                cout << d << ' ';
        }
        cout << endl;
}

// Local Variables: //
// compile-command: "g++ -std=c++17 test.cc" //
// End: //