suspend_never.cpp

#ifdef BEMAN_HAS_IMPORT_STD
import std;
#else
#include <coroutine>
#include <iostream>
#include <new>
#include <memory>
#endif
#include <beman/execution/execution.hpp>

namespace ex = beman::execution;

void* operator new(std::size_t n) {
    auto p = std::malloc(n);
    std::cout << "global new(" << n << ")->" << p << "\n";
    return p;
}
void operator delete(void* ptr) noexcept {
    std::cout << "global operator delete()" << ptr << "\n";
    std::free(ptr);
}

int main() {
    struct resource : std::pmr::memory_resource {
        void* do_allocate(std::size_t n, std::size_t a) override {
            auto p{std::malloc(n)};
            std::cout << "resource::allocate(" << n << ", " << a << ") -> " << p << "\n";
            return p;
        }
        void do_deallocate(void* p, std::size_t n, std::size_t a) override {
            std::cout << "resource::deallocate(" << p << ", " << n << ", " << a << ")\n";
            std::free(p);
        }
        bool do_is_equal(const std::pmr::memory_resource& other) const noexcept override { return this == &other; }
    } res{};

    ex::sync_wait(ex::write_env(
        std::suspend_never(), ex::env{ex::prop{ex::get_allocator, std::pmr::polymorphic_allocator<std::byte>(&res)}}));
}