//

// 11.9.small.features.cpp

// chapter 11 cpp23

// modern c++ tutorial

//

// created by changkun at changkun.de

// https://github.com/changkun/modern-cpp-tutorial

//

#include <bit>

#include <cstdint>

#include <iostream>

#include <string>

#include <vector>

// A function object whose call operator is static (C++23): no implicit

// object parameter, so it can be called without an instance overhead.

struct Add {

static int operator()(int a, int b) { return a + b; }

};

int main() {

// auto(x): an explicit decay-copy that produces a prvalue copy.

std::vector<int> v{1, 2, 3};

auto copy = auto(v);

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

// static operator()

std::cout << "Add: " << Add{}(2, 3) << '\n';

// std::string::contains (C++23)

std::string s = "modern c++";

std::cout << "contains: " << s.contains("c++") << '\n';

// std::byteswap (C++23)

std::cout << std::hex << "byteswap: "

<< std::byteswap(std::uint16_t{0x1234}) << std::dec << '\n';

// [[assume]] gives the optimizer a precondition it may rely on.

int x = 10;

[[assume(x > 0)]];

std::cout << "x = " << x << '\n';

}