usage-example.cc

/**
 *  \file usage-example.cc
 */

#include <functional>
#include <iostream>
#include <string>

//  \brief Nursling is owned by nursery.
class Nursling {
public:
    template<typename Fn, typename ...Args>
    Nursling(Fn&& fn, Args&& ...args) noexcept
    {
        std::cerr << "Nursling()\n";
    }

    ~Nursling(void) {
        std::cerr << "~Nursling()\n";
    }
};

#define CACTUS_CONCAT_IMPL(a, b)    a##_##b
#define CACTUS_CONCAT(a, b)         CACTUS_CONCAT_IMPL(a, b)

#if !defined(CACTUS_SALT)
#define CACTUS_SALT 19a83b68886c9c991c8431ececb31092
#endif

#if !defined(CACTUS_PREFIX)
#define CACTUS_PREFIX   CACTUS_CONCAT(cactus_coro, 19a83b68886c9c991c8431ececb31092)
#endif

#if !defined(CACTUS_SUFFIX)
#define CACTUS_SUFFIX   CACTUS_CONCAT(__LINE__, __COUNTER__)
#endif

#define CACTUS_IDENTIFIER       CACTUS_CONCAT(CACTUS_PREFIX, CACTUS_SUFFIX)
#define CACTUS_GO(var, fn, ...) auto &&var = Nursling(fn, ##__VA_ARGS__)

#define Go(fn, ...)             CACTUS_GO(CACTUS_IDENTIFIER, fn, ##__VA_ARGS__)

int main() {
    {
        Go([&] () {}, 42, "hello, ", std::string("world!"));
        std::cerr << "somewhere in the middle\n";
    }
    std::cerr << "out of scope\n";
    return 0;
}