#include <iostream>

int main()
{
   std::cout << "Computing the size of some C and C++ built-in variable types\n\n";

   std::cout << "Size of bool:               " << sizeof(bool) << '\n';
   std::cout << "Size of char:               " << sizeof(char) << '\n';
   std::cout << "Size of wchar_t:            " << sizeof(wchar_t) << '\n';
   std::cout << "Size of unsigned short int: " << sizeof(unsigned short) << '\n';
   std::cout << "Size of short:              " << sizeof(short) << '\n';
   std::cout << "Size of unsigned long int:  " << sizeof(unsigned long) << '\n';
   std::cout << "Size of long:               " << sizeof(long) << '\n';
   std::cout << "Size of int:                " << sizeof(int) << '\n';
   std::cout << "Size of unsigned int:       " << sizeof(unsigned int) << '\n';
   std::cout << "Size of float:              " << sizeof(float) << '\n';
   std::cout << "Size of double:             " << sizeof(double) << "\n\n";

   std::cout << "Size of std::size_t:        " << sizeof(std::size_t) << "\n\n";

   std::cout << "The output can change with compiler, processor type and OS\n\n";

   std::cout << "C++11 added several new fundamental variable types.\n";
   std::cout << "The values can change whether compiled as 32 or 64 bit.\n\n";

   std::cout << "Size of char16_t:           " << sizeof(char16_t) << '\n';
   std::cout << "Size of char32_t:           " << sizeof(char32_t) << '\n';
   std::cout << "Size of unsigned long long: " << sizeof(unsigned long long) << '\n';
   std::cout << "Size of long long:          " << sizeof(long long) << '\n';
   std::cout << "Size of long double:        " << sizeof(long double) << '\n';
   std::cout << "Size of nullptr:            " << sizeof(nullptr) << '\n';
}

#include <string>
#include <iostream>

int main() {
	const std::string str { "qwerty" };

	std::cout << "as ASCII - " << str << "  " << str.size() << "  " << str.length() << "  " << str.size() * sizeof(str[0]) << " bytes" << '\n';

	const std::wstring w { L"asdfgh" };

	std::wcout << "as wchar_t - " << w << "  " << w.size() << "  " << w.length() << "  " << w.size() * sizeof(w[0]) << " bytes" << '\n';

	const auto d { (char*)w.data() };

	for (int i = 0; i <= w.size() * sizeof(w[0]); ++i)
		std::cout << (int)d[i] << ' ';

	std::cout << '\n';

	std::u32string u { U"zxcvbn" };

	std::cout << "as u32" << "  " << u.size() << "  " << u.length() << "  " << u.size() * sizeof(u[0]) << " bytes" << '\n';

	const auto du { (char*)u.data() };

	for (int i = 0; i <= u.size() * sizeof(u[0]); ++i)
		std::cout << (int)du[i] << ' ';

	std::cout << '\n';
}

#include <string>
#include <iostream>
#include <iomanip>

int main() {
	const std::string s { "qwerty" };

	std::cout << "size is " << s.size() << '\n';

	std::cout << "-1 < " << s.size() << " is " << std::boolalpha << (-1 < s.size()) << '\n';
}

#include <iostream>

struct my_type
{
    int first ;
    int second ;
    constexpr explicit my_type( int a = 0, int b = 0 ) noexcept : first(a), second(b) {}
    constexpr operator int() const noexcept { return first + second ; }
};

constexpr my_type operator"" _mt( unsigned long long n ) noexcept { return my_type( int(n) ) ; }

int main()
{
    constexpr my_type seven = 7_mt ;

    int i ;
    std::cin >> i ;
    my_type mt(i) ;

    switch(mt)
    {
        case 5 : std::cout << "5\n" ; break ;
        case my_type(3) : std::cout << "3\n" ; break ;
        case seven : std::cout << "7\n" ; break ;
        case 123_mt : std::cout << "123\n" ; break ;
        default : std::cout << "something else\n" ;
    }
}