1   
//
1   
//
2   
// Copyright (c) 2025 Vinnie Falco (vinnie.falco@gmail.com)
2   
// Copyright (c) 2025 Vinnie Falco (vinnie.falco@gmail.com)
3   
//
3   
//
4   
// Distributed under the Boost Software License, Version 1.0. (See accompanying
4   
// Distributed under the Boost Software License, Version 1.0. (See accompanying
5   
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
5   
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6   
//
6   
//
7   
// Official repository: https://github.com/cppalliance/capy
7   
// Official repository: https://github.com/cppalliance/capy
8   
//
8   
//
9  
9  
10   
#ifndef BOOST_CAPY_RUN_HPP
10   
#ifndef BOOST_CAPY_RUN_HPP
11   
#define BOOST_CAPY_RUN_HPP
11   
#define BOOST_CAPY_RUN_HPP
12  
12  
13   
#include <boost/capy/detail/config.hpp>
13   
#include <boost/capy/detail/config.hpp>
14   
#include <boost/capy/detail/await_suspend_helper.hpp>
14   
#include <boost/capy/detail/await_suspend_helper.hpp>
15   
#include <boost/capy/detail/run.hpp>
15   
#include <boost/capy/detail/run.hpp>
16   
#include <boost/capy/concept/executor.hpp>
16   
#include <boost/capy/concept/executor.hpp>
17   
#include <boost/capy/concept/io_runnable.hpp>
17   
#include <boost/capy/concept/io_runnable.hpp>
18   
#include <boost/capy/ex/executor_ref.hpp>
18   
#include <boost/capy/ex/executor_ref.hpp>
19   
#include <coroutine>
19   
#include <coroutine>
20   
#include <boost/capy/ex/frame_allocator.hpp>
20   
#include <boost/capy/ex/frame_allocator.hpp>
21   
#include <boost/capy/ex/io_env.hpp>
21   
#include <boost/capy/ex/io_env.hpp>
22  
22  
23   
#include <memory_resource>
23   
#include <memory_resource>
24   
#include <stop_token>
24   
#include <stop_token>
25   
#include <type_traits>
25   
#include <type_traits>
26   
#include <utility>
26   
#include <utility>
27   
#include <variant>
27   
#include <variant>
28  
28  
29   
/*
29   
/*
30   
    Allocator Lifetime Strategy
30   
    Allocator Lifetime Strategy
31   
    ===========================
31   
    ===========================
32  
32  
33   
    When using run() with a custom allocator:
33   
    When using run() with a custom allocator:
34  
34  
35   
        co_await run(ex, alloc)(my_task());
35   
        co_await run(ex, alloc)(my_task());
36  
36  
37   
    The evaluation order is:
37   
    The evaluation order is:
38   
        1. run(ex, alloc) creates a temporary wrapper
38   
        1. run(ex, alloc) creates a temporary wrapper
39   
        2. my_task() allocates its coroutine frame using TLS
39   
        2. my_task() allocates its coroutine frame using TLS
40   
        3. operator() returns an awaitable
40   
        3. operator() returns an awaitable
41   
        4. Wrapper temporary is DESTROYED
41   
        4. Wrapper temporary is DESTROYED
42   
        5. co_await suspends caller, resumes task
42   
        5. co_await suspends caller, resumes task
43   
        6. Task body executes (wrapper is already dead!)
43   
        6. Task body executes (wrapper is already dead!)
44  
44  
45   
    Problem: The wrapper's frame_memory_resource dies before the task
45   
    Problem: The wrapper's frame_memory_resource dies before the task
46   
    body runs. When initial_suspend::await_resume() restores TLS from
46   
    body runs. When initial_suspend::await_resume() restores TLS from
47   
    the saved pointer, it would point to dead memory.
47   
    the saved pointer, it would point to dead memory.
48  
48  
49   
    Solution: Store a COPY of the allocator in the awaitable (not just
49   
    Solution: Store a COPY of the allocator in the awaitable (not just
50   
    the wrapper). The co_await mechanism extends the awaitable's lifetime
50   
    the wrapper). The co_await mechanism extends the awaitable's lifetime
51   
    until the await completes. In await_suspend, we overwrite the promise's
51   
    until the await completes. In await_suspend, we overwrite the promise's
52   
    saved frame_allocator pointer to point to the awaitable's resource.
52   
    saved frame_allocator pointer to point to the awaitable's resource.
53  
53  
54   
    This works because standard allocator copies are equivalent - memory
54   
    This works because standard allocator copies are equivalent - memory
55   
    allocated with one copy can be deallocated with another copy. The
55   
    allocated with one copy can be deallocated with another copy. The
56   
    task's own frame uses the footer-stored pointer (safe), while nested
56   
    task's own frame uses the footer-stored pointer (safe), while nested
57   
    task creation uses TLS pointing to the awaitable's resource (also safe).
57   
    task creation uses TLS pointing to the awaitable's resource (also safe).
58   
*/
58   
*/
59  
59  
60   
namespace boost::capy::detail {
60   
namespace boost::capy::detail {
61  
61  
62   
//----------------------------------------------------------
62   
//----------------------------------------------------------
63   
//
63   
//
64   
// dispatch_trampoline - cross-executor dispatch
64   
// dispatch_trampoline - cross-executor dispatch
65   
//
65   
//
66   
//----------------------------------------------------------
66   
//----------------------------------------------------------
67  
67  
68   
/** Minimal coroutine that dispatches through the caller's executor.
68   
/** Minimal coroutine that dispatches through the caller's executor.
69  
69  
70   
    Sits between the inner task and the parent when executors
70   
    Sits between the inner task and the parent when executors
71   
    diverge. The inner task's `final_suspend` resumes this
71   
    diverge. The inner task's `final_suspend` resumes this
72   
    trampoline via symmetric transfer. The trampoline's own
72   
    trampoline via symmetric transfer. The trampoline's own
73   
    `final_suspend` dispatches the parent through the caller's
73   
    `final_suspend` dispatches the parent through the caller's
74   
    executor to restore the correct execution context.
74   
    executor to restore the correct execution context.
75  
75  
76   
    The trampoline never touches the task's result.
76   
    The trampoline never touches the task's result.
77   
*/
77   
*/
78   
struct dispatch_trampoline
78   
struct dispatch_trampoline
79   
{
79   
{
80   
    struct promise_type
80   
    struct promise_type
81   
    {
81   
    {
82   
        executor_ref caller_ex_;
82   
        executor_ref caller_ex_;
83   
        std::coroutine_handle<> parent_;
83   
        std::coroutine_handle<> parent_;
84  
84  
85   
        dispatch_trampoline get_return_object() noexcept
85   
        dispatch_trampoline get_return_object() noexcept
86   
        {
86   
        {
87   
            return dispatch_trampoline{
87   
            return dispatch_trampoline{
88   
                std::coroutine_handle<promise_type>::from_promise(*this)};
88   
                std::coroutine_handle<promise_type>::from_promise(*this)};
89   
        }
89   
        }
90  
90  
91   
        std::suspend_always initial_suspend() noexcept { return {}; }
91   
        std::suspend_always initial_suspend() noexcept { return {}; }
92  
92  
93   
        auto final_suspend() noexcept
93   
        auto final_suspend() noexcept
94   
        {
94   
        {
95   
            struct awaiter
95   
            struct awaiter
96   
            {
96   
            {
97   
                promise_type* p_;
97   
                promise_type* p_;
98   
                bool await_ready() const noexcept { return false; }
98   
                bool await_ready() const noexcept { return false; }
99  
99  
100   
                auto await_suspend(
100   
                auto await_suspend(
101   
                    std::coroutine_handle<>) noexcept
101   
                    std::coroutine_handle<>) noexcept
102   
                {
102   
                {
103   
                    return detail::symmetric_transfer(
103   
                    return detail::symmetric_transfer(
104   
                        p_->caller_ex_.dispatch(p_->parent_));
104   
                        p_->caller_ex_.dispatch(p_->parent_));
105   
                }
105   
                }
106  
106  
107   
                void await_resume() const noexcept {}
107   
                void await_resume() const noexcept {}
108   
            };
108   
            };
109   
            return awaiter{this};
109   
            return awaiter{this};
110   
        }
110   
        }
111  
111  
112   
        void return_void() noexcept {}
112   
        void return_void() noexcept {}
113   
        void unhandled_exception() noexcept {}
113   
        void unhandled_exception() noexcept {}
114   
    };
114   
    };
115  
115  
116   
    std::coroutine_handle<promise_type> h_{nullptr};
116   
    std::coroutine_handle<promise_type> h_{nullptr};
117  
117  
118   
    dispatch_trampoline() noexcept = default;
118   
    dispatch_trampoline() noexcept = default;
119  
119  
120   
    ~dispatch_trampoline()
120   
    ~dispatch_trampoline()
121   
    {
121   
    {
122   
        if(h_) h_.destroy();
122   
        if(h_) h_.destroy();
123   
    }
123   
    }
124  
124  
125   
    dispatch_trampoline(dispatch_trampoline const&) = delete;
125   
    dispatch_trampoline(dispatch_trampoline const&) = delete;
126   
    dispatch_trampoline& operator=(dispatch_trampoline const&) = delete;
126   
    dispatch_trampoline& operator=(dispatch_trampoline const&) = delete;
127  
127  
128   
    dispatch_trampoline(dispatch_trampoline&& o) noexcept
128   
    dispatch_trampoline(dispatch_trampoline&& o) noexcept
129   
        : h_(std::exchange(o.h_, nullptr)) {}
129   
        : h_(std::exchange(o.h_, nullptr)) {}
130  
130  
131   
    dispatch_trampoline& operator=(dispatch_trampoline&& o) noexcept
131   
    dispatch_trampoline& operator=(dispatch_trampoline&& o) noexcept
132   
    {
132   
    {
133   
        if(this != &o)
133   
        if(this != &o)
134   
        {
134   
        {
135   
            if(h_) h_.destroy();
135   
            if(h_) h_.destroy();
136   
            h_ = std::exchange(o.h_, nullptr);
136   
            h_ = std::exchange(o.h_, nullptr);
137   
        }
137   
        }
138   
        return *this;
138   
        return *this;
139   
    }
139   
    }
140  
140  
141   
private:
141   
private:
142   
    explicit dispatch_trampoline(std::coroutine_handle<promise_type> h) noexcept
142   
    explicit dispatch_trampoline(std::coroutine_handle<promise_type> h) noexcept
143   
        : h_(h) {}
143   
        : h_(h) {}
144   
};
144   
};
145  
145  
146   
inline dispatch_trampoline make_dispatch_trampoline()
146   
inline dispatch_trampoline make_dispatch_trampoline()
147   
{
147   
{
148   
    co_return;
148   
    co_return;
149   
}
149   
}
150  
150  
151   
//----------------------------------------------------------
151   
//----------------------------------------------------------
152   
//
152   
//
153   
// run_awaitable_ex - with executor (executor switch)
153   
// run_awaitable_ex - with executor (executor switch)
154   
//
154   
//
155   
//----------------------------------------------------------
155   
//----------------------------------------------------------
156  
156  
157   
/** Awaitable that binds an IoRunnable to a specific executor.
157   
/** Awaitable that binds an IoRunnable to a specific executor.
158  
158  
159   
    Stores the executor and inner task by value. When co_awaited, the
159   
    Stores the executor and inner task by value. When co_awaited, the
160   
    co_await expression's lifetime extension keeps both alive for the
160   
    co_await expression's lifetime extension keeps both alive for the
161   
    duration of the operation.
161   
    duration of the operation.
162  
162  
163   
    A dispatch trampoline handles the executor switch on completion:
163   
    A dispatch trampoline handles the executor switch on completion:
164   
    the inner task's `final_suspend` resumes the trampoline, which
164   
    the inner task's `final_suspend` resumes the trampoline, which
165   
    dispatches back through the caller's executor.
165   
    dispatches back through the caller's executor.
166  
166  
167   
    The `io_env` is owned by this awaitable and is guaranteed to
167   
    The `io_env` is owned by this awaitable and is guaranteed to
168   
    outlive the inner task and all awaitables in its chain. Awaitables
168   
    outlive the inner task and all awaitables in its chain. Awaitables
169   
    may store `io_env const*` without concern for dangling references.
169   
    may store `io_env const*` without concern for dangling references.
170  
170  
171   
    @tparam Task The IoRunnable type
171   
    @tparam Task The IoRunnable type
172   
    @tparam Ex The executor type
172   
    @tparam Ex The executor type
173   
    @tparam InheritStopToken If true, inherit caller's stop token
173   
    @tparam InheritStopToken If true, inherit caller's stop token
174   
    @tparam Alloc The allocator type (void for no allocator)
174   
    @tparam Alloc The allocator type (void for no allocator)
175   
*/
175   
*/
176   
template<IoRunnable Task, Executor Ex, bool InheritStopToken, class Alloc = void>
176   
template<IoRunnable Task, Executor Ex, bool InheritStopToken, class Alloc = void>
177   
struct [[nodiscard]] run_awaitable_ex
177   
struct [[nodiscard]] run_awaitable_ex
178   
{
178   
{
179   
    Ex ex_;
179   
    Ex ex_;
180   
    frame_memory_resource<Alloc> resource_;
180   
    frame_memory_resource<Alloc> resource_;
181   
    std::conditional_t<InheritStopToken, std::monostate, std::stop_token> st_;
181   
    std::conditional_t<InheritStopToken, std::monostate, std::stop_token> st_;
182   
    io_env env_;
182   
    io_env env_;
183   
    dispatch_trampoline tr_;
183   
    dispatch_trampoline tr_;
184   
    Task inner_;  // Last: destroyed first, while env_ is still valid
184   
    Task inner_;  // Last: destroyed first, while env_ is still valid
185  
185  
186   
    // void allocator, inherit stop token
186   
    // void allocator, inherit stop token
187   
    run_awaitable_ex(Ex ex, Task inner)
187   
    run_awaitable_ex(Ex ex, Task inner)
188   
        requires (InheritStopToken && std::is_void_v<Alloc>)
188   
        requires (InheritStopToken && std::is_void_v<Alloc>)
189   
        : ex_(std::move(ex))
189   
        : ex_(std::move(ex))
190   
        , inner_(std::move(inner))
190   
        , inner_(std::move(inner))
191   
    {
191   
    {
192   
    }
192   
    }
193  
193  
194   
    // void allocator, explicit stop token
194   
    // void allocator, explicit stop token
195   
    run_awaitable_ex(Ex ex, Task inner, std::stop_token st)
195   
    run_awaitable_ex(Ex ex, Task inner, std::stop_token st)
196   
        requires (!InheritStopToken && std::is_void_v<Alloc>)
196   
        requires (!InheritStopToken && std::is_void_v<Alloc>)
197   
        : ex_(std::move(ex))
197   
        : ex_(std::move(ex))
198   
        , st_(std::move(st))
198   
        , st_(std::move(st))
199   
        , inner_(std::move(inner))
199   
        , inner_(std::move(inner))
200   
    {
200   
    {
201   
    }
201   
    }
202  
202  
203   
    // with allocator, inherit stop token (use template to avoid void parameter)
203   
    // with allocator, inherit stop token (use template to avoid void parameter)
204   
    template<class A>
204   
    template<class A>
205   
        requires (InheritStopToken && !std::is_void_v<Alloc> && std::same_as<A, Alloc>)
205   
        requires (InheritStopToken && !std::is_void_v<Alloc> && std::same_as<A, Alloc>)
206   
    run_awaitable_ex(Ex ex, A alloc, Task inner)
206   
    run_awaitable_ex(Ex ex, A alloc, Task inner)
207   
        : ex_(std::move(ex))
207   
        : ex_(std::move(ex))
208   
        , resource_(std::move(alloc))
208   
        , resource_(std::move(alloc))
209   
        , inner_(std::move(inner))
209   
        , inner_(std::move(inner))
210   
    {
210   
    {
211   
    }
211   
    }
212  
212  
213   
    // with allocator, explicit stop token (use template to avoid void parameter)
213   
    // with allocator, explicit stop token (use template to avoid void parameter)
214   
    template<class A>
214   
    template<class A>
215   
        requires (!InheritStopToken && !std::is_void_v<Alloc> && std::same_as<A, Alloc>)
215   
        requires (!InheritStopToken && !std::is_void_v<Alloc> && std::same_as<A, Alloc>)
216   
    run_awaitable_ex(Ex ex, A alloc, Task inner, std::stop_token st)
216   
    run_awaitable_ex(Ex ex, A alloc, Task inner, std::stop_token st)
217   
        : ex_(std::move(ex))
217   
        : ex_(std::move(ex))
218   
        , resource_(std::move(alloc))
218   
        , resource_(std::move(alloc))
219   
        , st_(std::move(st))
219   
        , st_(std::move(st))
220   
        , inner_(std::move(inner))
220   
        , inner_(std::move(inner))
221   
    {
221   
    {
222   
    }
222   
    }
223  
223  
224   
    bool await_ready() const noexcept
224   
    bool await_ready() const noexcept
225   
    {
225   
    {
226   
        return inner_.await_ready();
226   
        return inner_.await_ready();
227   
    }
227   
    }
228  
228  
229   
    decltype(auto) await_resume()
229   
    decltype(auto) await_resume()
230   
    {
230   
    {
231   
        return inner_.await_resume();
231   
        return inner_.await_resume();
232   
    }
232   
    }
233  
233  
234   
    std::coroutine_handle<> await_suspend(std::coroutine_handle<> cont, io_env const* caller_env)
234   
    std::coroutine_handle<> await_suspend(std::coroutine_handle<> cont, io_env const* caller_env)
235   
    {
235   
    {
236   
        tr_ = make_dispatch_trampoline();
236   
        tr_ = make_dispatch_trampoline();
237   
        tr_.h_.promise().caller_ex_ = caller_env->executor;
237   
        tr_.h_.promise().caller_ex_ = caller_env->executor;
238   
        tr_.h_.promise().parent_ = cont;
238   
        tr_.h_.promise().parent_ = cont;
239  
239  
240   
        auto h = inner_.handle();
240   
        auto h = inner_.handle();
241   
        auto& p = h.promise();
241   
        auto& p = h.promise();
242   
        p.set_continuation(tr_.h_);
242   
        p.set_continuation(tr_.h_);
243  
243  
244   
        env_.executor = ex_;
244   
        env_.executor = ex_;
245   
        if constexpr (InheritStopToken)
245   
        if constexpr (InheritStopToken)
246   
            env_.stop_token = caller_env->stop_token;
246   
            env_.stop_token = caller_env->stop_token;
247   
        else
247   
        else
248   
            env_.stop_token = st_;
248   
            env_.stop_token = st_;
249  
249  
250   
        if constexpr (!std::is_void_v<Alloc>)
250   
        if constexpr (!std::is_void_v<Alloc>)
251   
            env_.frame_allocator = resource_.get();
251   
            env_.frame_allocator = resource_.get();
252   
        else
252   
        else
253   
            env_.frame_allocator = caller_env->frame_allocator;
253   
            env_.frame_allocator = caller_env->frame_allocator;
254  
254  
255   
        p.set_environment(&env_);
255   
        p.set_environment(&env_);
256   
        return h;
256   
        return h;
257   
    }
257   
    }
258  
258  
259   
    // Non-copyable
259   
    // Non-copyable
260   
    run_awaitable_ex(run_awaitable_ex const&) = delete;
260   
    run_awaitable_ex(run_awaitable_ex const&) = delete;
261   
    run_awaitable_ex& operator=(run_awaitable_ex const&) = delete;
261   
    run_awaitable_ex& operator=(run_awaitable_ex const&) = delete;
262  
262  
263   
    // Movable (no noexcept - Task may throw)
263   
    // Movable (no noexcept - Task may throw)
264   
    run_awaitable_ex(run_awaitable_ex&&) = default;
264   
    run_awaitable_ex(run_awaitable_ex&&) = default;
265   
    run_awaitable_ex& operator=(run_awaitable_ex&&) = default;
265   
    run_awaitable_ex& operator=(run_awaitable_ex&&) = default;
266   
};
266   
};
267  
267  
268   
//----------------------------------------------------------
268   
//----------------------------------------------------------
269   
//
269   
//
270   
// run_awaitable - no executor (inherits caller's executor)
270   
// run_awaitable - no executor (inherits caller's executor)
271   
//
271   
//
272   
//----------------------------------------------------------
272   
//----------------------------------------------------------
273  
273  
274   
/** Awaitable that runs a task with optional stop_token override.
274   
/** Awaitable that runs a task with optional stop_token override.
275  
275  
276   
    Does NOT store an executor - the task inherits the caller's executor
276   
    Does NOT store an executor - the task inherits the caller's executor
277   
    directly. Executors always match, so no dispatch trampoline is needed.
277   
    directly. Executors always match, so no dispatch trampoline is needed.
278   
    The inner task's `final_suspend` resumes the parent directly via
278   
    The inner task's `final_suspend` resumes the parent directly via
279   
    unconditional symmetric transfer.
279   
    unconditional symmetric transfer.
280  
280  
281   
    @tparam Task The IoRunnable type
281   
    @tparam Task The IoRunnable type
282   
    @tparam InheritStopToken If true, inherit caller's stop token
282   
    @tparam InheritStopToken If true, inherit caller's stop token
283   
    @tparam Alloc The allocator type (void for no allocator)
283   
    @tparam Alloc The allocator type (void for no allocator)
284   
*/
284   
*/
285   
template<IoRunnable Task, bool InheritStopToken, class Alloc = void>
285   
template<IoRunnable Task, bool InheritStopToken, class Alloc = void>
286   
struct [[nodiscard]] run_awaitable
286   
struct [[nodiscard]] run_awaitable
287   
{
287   
{
288   
    frame_memory_resource<Alloc> resource_;
288   
    frame_memory_resource<Alloc> resource_;
289   
    std::conditional_t<InheritStopToken, std::monostate, std::stop_token> st_;
289   
    std::conditional_t<InheritStopToken, std::monostate, std::stop_token> st_;
290   
    io_env env_;
290   
    io_env env_;
291   
    Task inner_;  // Last: destroyed first, while env_ is still valid
291   
    Task inner_;  // Last: destroyed first, while env_ is still valid
292  
292  
293   
    // void allocator, inherit stop token
293   
    // void allocator, inherit stop token
294   
    explicit run_awaitable(Task inner)
294   
    explicit run_awaitable(Task inner)
295   
        requires (InheritStopToken && std::is_void_v<Alloc>)
295   
        requires (InheritStopToken && std::is_void_v<Alloc>)
296   
        : inner_(std::move(inner))
296   
        : inner_(std::move(inner))
297   
    {
297   
    {
298   
    }
298   
    }
299  
299  
300   
    // void allocator, explicit stop token
300   
    // void allocator, explicit stop token
301   
    run_awaitable(Task inner, std::stop_token st)
301   
    run_awaitable(Task inner, std::stop_token st)
302   
        requires (!InheritStopToken && std::is_void_v<Alloc>)
302   
        requires (!InheritStopToken && std::is_void_v<Alloc>)
303   
        : st_(std::move(st))
303   
        : st_(std::move(st))
304   
        , inner_(std::move(inner))
304   
        , inner_(std::move(inner))
305   
    {
305   
    {
306   
    }
306   
    }
307  
307  
308   
    // with allocator, inherit stop token (use template to avoid void parameter)
308   
    // with allocator, inherit stop token (use template to avoid void parameter)
309   
    template<class A>
309   
    template<class A>
310   
        requires (InheritStopToken && !std::is_void_v<Alloc> && std::same_as<A, Alloc>)
310   
        requires (InheritStopToken && !std::is_void_v<Alloc> && std::same_as<A, Alloc>)
311   
    run_awaitable(A alloc, Task inner)
311   
    run_awaitable(A alloc, Task inner)
312   
        : resource_(std::move(alloc))
312   
        : resource_(std::move(alloc))
313   
        , inner_(std::move(inner))
313   
        , inner_(std::move(inner))
314   
    {
314   
    {
315   
    }
315   
    }
316  
316  
317   
    // with allocator, explicit stop token (use template to avoid void parameter)
317   
    // with allocator, explicit stop token (use template to avoid void parameter)
318   
    template<class A>
318   
    template<class A>
319   
        requires (!InheritStopToken && !std::is_void_v<Alloc> && std::same_as<A, Alloc>)
319   
        requires (!InheritStopToken && !std::is_void_v<Alloc> && std::same_as<A, Alloc>)
320   
    run_awaitable(A alloc, Task inner, std::stop_token st)
320   
    run_awaitable(A alloc, Task inner, std::stop_token st)
321   
        : resource_(std::move(alloc))
321   
        : resource_(std::move(alloc))
322   
        , st_(std::move(st))
322   
        , st_(std::move(st))
323   
        , inner_(std::move(inner))
323   
        , inner_(std::move(inner))
324   
    {
324   
    {
325   
    }
325   
    }
326  
326  
327   
    bool await_ready() const noexcept
327   
    bool await_ready() const noexcept
328   
    {
328   
    {
329   
        return inner_.await_ready();
329   
        return inner_.await_ready();
330   
    }
330   
    }
331  
331  
332   
    decltype(auto) await_resume()
332   
    decltype(auto) await_resume()
333   
    {
333   
    {
334   
        return inner_.await_resume();
334   
        return inner_.await_resume();
335   
    }
335   
    }
336  
336  
337   
    std::coroutine_handle<> await_suspend(std::coroutine_handle<> cont, io_env const* caller_env)
337   
    std::coroutine_handle<> await_suspend(std::coroutine_handle<> cont, io_env const* caller_env)
338   
    {
338   
    {
339   
        auto h = inner_.handle();
339   
        auto h = inner_.handle();
340   
        auto& p = h.promise();
340   
        auto& p = h.promise();
341   
        p.set_continuation(cont);
341   
        p.set_continuation(cont);
342  
342  
343   
        env_.executor = caller_env->executor;
343   
        env_.executor = caller_env->executor;
344   
        if constexpr (InheritStopToken)
344   
        if constexpr (InheritStopToken)
345   
            env_.stop_token = caller_env->stop_token;
345   
            env_.stop_token = caller_env->stop_token;
346   
        else
346   
        else
347   
            env_.stop_token = st_;
347   
            env_.stop_token = st_;
348  
348  
349   
        if constexpr (!std::is_void_v<Alloc>)
349   
        if constexpr (!std::is_void_v<Alloc>)
350   
            env_.frame_allocator = resource_.get();
350   
            env_.frame_allocator = resource_.get();
351   
        else
351   
        else
352   
            env_.frame_allocator = caller_env->frame_allocator;
352   
            env_.frame_allocator = caller_env->frame_allocator;
353  
353  
354   
        p.set_environment(&env_);
354   
        p.set_environment(&env_);
355   
        return h;
355   
        return h;
356   
    }
356   
    }
357  
357  
358   
    // Non-copyable
358   
    // Non-copyable
359   
    run_awaitable(run_awaitable const&) = delete;
359   
    run_awaitable(run_awaitable const&) = delete;
360   
    run_awaitable& operator=(run_awaitable const&) = delete;
360   
    run_awaitable& operator=(run_awaitable const&) = delete;
361  
361  
362   
    // Movable (no noexcept - Task may throw)
362   
    // Movable (no noexcept - Task may throw)
363   
    run_awaitable(run_awaitable&&) = default;
363   
    run_awaitable(run_awaitable&&) = default;
364   
    run_awaitable& operator=(run_awaitable&&) = default;
364   
    run_awaitable& operator=(run_awaitable&&) = default;
365   
};
365   
};
366  
366  
367   
//----------------------------------------------------------
367   
//----------------------------------------------------------
368   
//
368   
//
369   
// run_wrapper_ex - with executor
369   
// run_wrapper_ex - with executor
370   
//
370   
//
371   
//----------------------------------------------------------
371   
//----------------------------------------------------------
372  
372  
373   
/** Wrapper returned by run(ex, ...) that accepts a task for execution.
373   
/** Wrapper returned by run(ex, ...) that accepts a task for execution.
374  
374  
375   
    @tparam Ex The executor type.
375   
    @tparam Ex The executor type.
376   
    @tparam InheritStopToken If true, inherit caller's stop token.
376   
    @tparam InheritStopToken If true, inherit caller's stop token.
377   
    @tparam Alloc The allocator type (void for no allocator).
377   
    @tparam Alloc The allocator type (void for no allocator).
378   
*/
378   
*/
379   
template<Executor Ex, bool InheritStopToken, class Alloc>
379   
template<Executor Ex, bool InheritStopToken, class Alloc>
380   
class [[nodiscard]] run_wrapper_ex
380   
class [[nodiscard]] run_wrapper_ex
381   
{
381   
{
382   
    Ex ex_;
382   
    Ex ex_;
383   
    std::conditional_t<InheritStopToken, std::monostate, std::stop_token> st_;
383   
    std::conditional_t<InheritStopToken, std::monostate, std::stop_token> st_;
384   
    frame_memory_resource<Alloc> resource_;
384   
    frame_memory_resource<Alloc> resource_;
385   
    Alloc alloc_;  // Copy to pass to awaitable
385   
    Alloc alloc_;  // Copy to pass to awaitable
386  
386  
387   
public:
387   
public:
388   
    run_wrapper_ex(Ex ex, Alloc alloc)
388   
    run_wrapper_ex(Ex ex, Alloc alloc)
389   
        requires InheritStopToken
389   
        requires InheritStopToken
390   
        : ex_(std::move(ex))
390   
        : ex_(std::move(ex))
391   
        , resource_(alloc)
391   
        , resource_(alloc)
392   
        , alloc_(std::move(alloc))
392   
        , alloc_(std::move(alloc))
393   
    {
393   
    {
394   
        set_current_frame_allocator(&resource_);
394   
        set_current_frame_allocator(&resource_);
395   
    }
395   
    }
396  
396  
397   
    run_wrapper_ex(Ex ex, std::stop_token st, Alloc alloc)
397   
    run_wrapper_ex(Ex ex, std::stop_token st, Alloc alloc)
398   
        requires (!InheritStopToken)
398   
        requires (!InheritStopToken)
399   
        : ex_(std::move(ex))
399   
        : ex_(std::move(ex))
400   
        , st_(std::move(st))
400   
        , st_(std::move(st))
401   
        , resource_(alloc)
401   
        , resource_(alloc)
402   
        , alloc_(std::move(alloc))
402   
        , alloc_(std::move(alloc))
403   
    {
403   
    {
404   
        set_current_frame_allocator(&resource_);
404   
        set_current_frame_allocator(&resource_);
405   
    }
405   
    }
406  
406  
407   
    // Non-copyable, non-movable (must be used immediately)
407   
    // Non-copyable, non-movable (must be used immediately)
408   
    run_wrapper_ex(run_wrapper_ex const&) = delete;
408   
    run_wrapper_ex(run_wrapper_ex const&) = delete;
409   
    run_wrapper_ex(run_wrapper_ex&&) = delete;
409   
    run_wrapper_ex(run_wrapper_ex&&) = delete;
410   
    run_wrapper_ex& operator=(run_wrapper_ex const&) = delete;
410   
    run_wrapper_ex& operator=(run_wrapper_ex const&) = delete;
411   
    run_wrapper_ex& operator=(run_wrapper_ex&&) = delete;
411   
    run_wrapper_ex& operator=(run_wrapper_ex&&) = delete;
412  
412  
413   
    template<IoRunnable Task>
413   
    template<IoRunnable Task>
414   
    [[nodiscard]] auto operator()(Task t) &&
414   
    [[nodiscard]] auto operator()(Task t) &&
415   
    {
415   
    {
416   
        if constexpr (InheritStopToken)
416   
        if constexpr (InheritStopToken)
417   
            return run_awaitable_ex<Task, Ex, true, Alloc>{
417   
            return run_awaitable_ex<Task, Ex, true, Alloc>{
418   
                std::move(ex_), std::move(alloc_), std::move(t)};
418   
                std::move(ex_), std::move(alloc_), std::move(t)};
419   
        else
419   
        else
420   
            return run_awaitable_ex<Task, Ex, false, Alloc>{
420   
            return run_awaitable_ex<Task, Ex, false, Alloc>{
421   
                std::move(ex_), std::move(alloc_), std::move(t), std::move(st_)};
421   
                std::move(ex_), std::move(alloc_), std::move(t), std::move(st_)};
422   
    }
422   
    }
423   
};
423   
};
424  
424  
425   
/// Specialization for memory_resource* - stores pointer directly.
425   
/// Specialization for memory_resource* - stores pointer directly.
426   
template<Executor Ex, bool InheritStopToken>
426   
template<Executor Ex, bool InheritStopToken>
427   
class [[nodiscard]] run_wrapper_ex<Ex, InheritStopToken, std::pmr::memory_resource*>
427   
class [[nodiscard]] run_wrapper_ex<Ex, InheritStopToken, std::pmr::memory_resource*>
428   
{
428   
{
429   
    Ex ex_;
429   
    Ex ex_;
430   
    std::conditional_t<InheritStopToken, std::monostate, std::stop_token> st_;
430   
    std::conditional_t<InheritStopToken, std::monostate, std::stop_token> st_;
431   
    std::pmr::memory_resource* mr_;
431   
    std::pmr::memory_resource* mr_;
432  
432  
433   
public:
433   
public:
434   
    run_wrapper_ex(Ex ex, std::pmr::memory_resource* mr)
434   
    run_wrapper_ex(Ex ex, std::pmr::memory_resource* mr)
435   
        requires InheritStopToken
435   
        requires InheritStopToken
436   
        : ex_(std::move(ex))
436   
        : ex_(std::move(ex))
437   
        , mr_(mr)
437   
        , mr_(mr)
438   
    {
438   
    {
439   
        set_current_frame_allocator(mr_);
439   
        set_current_frame_allocator(mr_);
440   
    }
440   
    }
441  
441  
442   
    run_wrapper_ex(Ex ex, std::stop_token st, std::pmr::memory_resource* mr)
442   
    run_wrapper_ex(Ex ex, std::stop_token st, std::pmr::memory_resource* mr)
443   
        requires (!InheritStopToken)
443   
        requires (!InheritStopToken)
444   
        : ex_(std::move(ex))
444   
        : ex_(std::move(ex))
445   
        , st_(std::move(st))
445   
        , st_(std::move(st))
446   
        , mr_(mr)
446   
        , mr_(mr)
447   
    {
447   
    {
448   
        set_current_frame_allocator(mr_);
448   
        set_current_frame_allocator(mr_);
449   
    }
449   
    }
450  
450  
451   
    // Non-copyable, non-movable (must be used immediately)
451   
    // Non-copyable, non-movable (must be used immediately)
452   
    run_wrapper_ex(run_wrapper_ex const&) = delete;
452   
    run_wrapper_ex(run_wrapper_ex const&) = delete;
453   
    run_wrapper_ex(run_wrapper_ex&&) = delete;
453   
    run_wrapper_ex(run_wrapper_ex&&) = delete;
454   
    run_wrapper_ex& operator=(run_wrapper_ex const&) = delete;
454   
    run_wrapper_ex& operator=(run_wrapper_ex const&) = delete;
455   
    run_wrapper_ex& operator=(run_wrapper_ex&&) = delete;
455   
    run_wrapper_ex& operator=(run_wrapper_ex&&) = delete;
456  
456  
457   
    template<IoRunnable Task>
457   
    template<IoRunnable Task>
458   
    [[nodiscard]] auto operator()(Task t) &&
458   
    [[nodiscard]] auto operator()(Task t) &&
459   
    {
459   
    {
460   
        if constexpr (InheritStopToken)
460   
        if constexpr (InheritStopToken)
461   
            return run_awaitable_ex<Task, Ex, true, std::pmr::memory_resource*>{
461   
            return run_awaitable_ex<Task, Ex, true, std::pmr::memory_resource*>{
462   
                std::move(ex_), mr_, std::move(t)};
462   
                std::move(ex_), mr_, std::move(t)};
463   
        else
463   
        else
464   
            return run_awaitable_ex<Task, Ex, false, std::pmr::memory_resource*>{
464   
            return run_awaitable_ex<Task, Ex, false, std::pmr::memory_resource*>{
465   
                std::move(ex_), mr_, std::move(t), std::move(st_)};
465   
                std::move(ex_), mr_, std::move(t), std::move(st_)};
466   
    }
466   
    }
467   
};
467   
};
468  
468  
469   
/// Specialization for no allocator (void).
469   
/// Specialization for no allocator (void).
470   
template<Executor Ex, bool InheritStopToken>
470   
template<Executor Ex, bool InheritStopToken>
471   
class [[nodiscard]] run_wrapper_ex<Ex, InheritStopToken, void>
471   
class [[nodiscard]] run_wrapper_ex<Ex, InheritStopToken, void>
472   
{
472   
{
473   
    Ex ex_;
473   
    Ex ex_;
474   
    std::conditional_t<InheritStopToken, std::monostate, std::stop_token> st_;
474   
    std::conditional_t<InheritStopToken, std::monostate, std::stop_token> st_;
475  
475  
476   
public:
476   
public:
477   
    explicit run_wrapper_ex(Ex ex)
477   
    explicit run_wrapper_ex(Ex ex)
478   
        requires InheritStopToken
478   
        requires InheritStopToken
479   
        : ex_(std::move(ex))
479   
        : ex_(std::move(ex))
480   
    {
480   
    {
481   
    }
481   
    }
482  
482  
483   
    run_wrapper_ex(Ex ex, std::stop_token st)
483   
    run_wrapper_ex(Ex ex, std::stop_token st)
484   
        requires (!InheritStopToken)
484   
        requires (!InheritStopToken)
485   
        : ex_(std::move(ex))
485   
        : ex_(std::move(ex))
486   
        , st_(std::move(st))
486   
        , st_(std::move(st))
487   
    {
487   
    {
488   
    }
488   
    }
489  
489  
490   
    // Non-copyable, non-movable (must be used immediately)
490   
    // Non-copyable, non-movable (must be used immediately)
491   
    run_wrapper_ex(run_wrapper_ex const&) = delete;
491   
    run_wrapper_ex(run_wrapper_ex const&) = delete;
492   
    run_wrapper_ex(run_wrapper_ex&&) = delete;
492   
    run_wrapper_ex(run_wrapper_ex&&) = delete;
493   
    run_wrapper_ex& operator=(run_wrapper_ex const&) = delete;
493   
    run_wrapper_ex& operator=(run_wrapper_ex const&) = delete;
494   
    run_wrapper_ex& operator=(run_wrapper_ex&&) = delete;
494   
    run_wrapper_ex& operator=(run_wrapper_ex&&) = delete;
495  
495  
496   
    template<IoRunnable Task>
496   
    template<IoRunnable Task>
497   
    [[nodiscard]] auto operator()(Task t) &&
497   
    [[nodiscard]] auto operator()(Task t) &&
498   
    {
498   
    {
499   
        if constexpr (InheritStopToken)
499   
        if constexpr (InheritStopToken)
500   
            return run_awaitable_ex<Task, Ex, true>{
500   
            return run_awaitable_ex<Task, Ex, true>{
501   
                std::move(ex_), std::move(t)};
501   
                std::move(ex_), std::move(t)};
502   
        else
502   
        else
503   
            return run_awaitable_ex<Task, Ex, false>{
503   
            return run_awaitable_ex<Task, Ex, false>{
504   
                std::move(ex_), std::move(t), std::move(st_)};
504   
                std::move(ex_), std::move(t), std::move(st_)};
505   
    }
505   
    }
506   
};
506   
};
507  
507  
508   
//----------------------------------------------------------
508   
//----------------------------------------------------------
509   
//
509   
//
510   
// run_wrapper - no executor (inherits caller's executor)
510   
// run_wrapper - no executor (inherits caller's executor)
511   
//
511   
//
512   
//----------------------------------------------------------
512   
//----------------------------------------------------------
513  
513  
514   
/** Wrapper returned by run(st) or run(alloc) that accepts a task.
514   
/** Wrapper returned by run(st) or run(alloc) that accepts a task.
515  
515  
516   
    @tparam InheritStopToken If true, inherit caller's stop token.
516   
    @tparam InheritStopToken If true, inherit caller's stop token.
517   
    @tparam Alloc The allocator type (void for no allocator).
517   
    @tparam Alloc The allocator type (void for no allocator).
518   
*/
518   
*/
519   
template<bool InheritStopToken, class Alloc>
519   
template<bool InheritStopToken, class Alloc>
520   
class [[nodiscard]] run_wrapper
520   
class [[nodiscard]] run_wrapper
521   
{
521   
{
522   
    std::conditional_t<InheritStopToken, std::monostate, std::stop_token> st_;
522   
    std::conditional_t<InheritStopToken, std::monostate, std::stop_token> st_;
523   
    frame_memory_resource<Alloc> resource_;
523   
    frame_memory_resource<Alloc> resource_;
524   
    Alloc alloc_;  // Copy to pass to awaitable
524   
    Alloc alloc_;  // Copy to pass to awaitable
525  
525  
526   
public:
526   
public:
527   
    explicit run_wrapper(Alloc alloc)
527   
    explicit run_wrapper(Alloc alloc)
528   
        requires InheritStopToken
528   
        requires InheritStopToken
529   
        : resource_(alloc)
529   
        : resource_(alloc)
530   
        , alloc_(std::move(alloc))
530   
        , alloc_(std::move(alloc))
531   
    {
531   
    {
532   
        set_current_frame_allocator(&resource_);
532   
        set_current_frame_allocator(&resource_);
533   
    }
533   
    }
534  
534  
535   
    run_wrapper(std::stop_token st, Alloc alloc)
535   
    run_wrapper(std::stop_token st, Alloc alloc)
536   
        requires (!InheritStopToken)
536   
        requires (!InheritStopToken)
537   
        : st_(std::move(st))
537   
        : st_(std::move(st))
538   
        , resource_(alloc)
538   
        , resource_(alloc)
539   
        , alloc_(std::move(alloc))
539   
        , alloc_(std::move(alloc))
540   
    {
540   
    {
541   
        set_current_frame_allocator(&resource_);
541   
        set_current_frame_allocator(&resource_);
542   
    }
542   
    }
543  
543  
544   
    // Non-copyable, non-movable (must be used immediately)
544   
    // Non-copyable, non-movable (must be used immediately)
545   
    run_wrapper(run_wrapper const&) = delete;
545   
    run_wrapper(run_wrapper const&) = delete;
546   
    run_wrapper(run_wrapper&&) = delete;
546   
    run_wrapper(run_wrapper&&) = delete;
547   
    run_wrapper& operator=(run_wrapper const&) = delete;
547   
    run_wrapper& operator=(run_wrapper const&) = delete;
548   
    run_wrapper& operator=(run_wrapper&&) = delete;
548   
    run_wrapper& operator=(run_wrapper&&) = delete;
549  
549  
550   
    template<IoRunnable Task>
550   
    template<IoRunnable Task>
551   
    [[nodiscard]] auto operator()(Task t) &&
551   
    [[nodiscard]] auto operator()(Task t) &&
552   
    {
552   
    {
553   
        if constexpr (InheritStopToken)
553   
        if constexpr (InheritStopToken)
554   
            return run_awaitable<Task, true, Alloc>{
554   
            return run_awaitable<Task, true, Alloc>{
555   
                std::move(alloc_), std::move(t)};
555   
                std::move(alloc_), std::move(t)};
556   
        else
556   
        else
557   
            return run_awaitable<Task, false, Alloc>{
557   
            return run_awaitable<Task, false, Alloc>{
558   
                std::move(alloc_), std::move(t), std::move(st_)};
558   
                std::move(alloc_), std::move(t), std::move(st_)};
559   
    }
559   
    }
560   
};
560   
};
561  
561  
562   
/// Specialization for memory_resource* - stores pointer directly.
562   
/// Specialization for memory_resource* - stores pointer directly.
563   
template<bool InheritStopToken>
563   
template<bool InheritStopToken>
564   
class [[nodiscard]] run_wrapper<InheritStopToken, std::pmr::memory_resource*>
564   
class [[nodiscard]] run_wrapper<InheritStopToken, std::pmr::memory_resource*>
565   
{
565   
{
566   
    std::conditional_t<InheritStopToken, std::monostate, std::stop_token> st_;
566   
    std::conditional_t<InheritStopToken, std::monostate, std::stop_token> st_;
567   
    std::pmr::memory_resource* mr_;
567   
    std::pmr::memory_resource* mr_;
568  
568  
569   
public:
569   
public:
570   
    explicit run_wrapper(std::pmr::memory_resource* mr)
570   
    explicit run_wrapper(std::pmr::memory_resource* mr)
571   
        requires InheritStopToken
571   
        requires InheritStopToken
572   
        : mr_(mr)
572   
        : mr_(mr)
573   
    {
573   
    {
574   
        set_current_frame_allocator(mr_);
574   
        set_current_frame_allocator(mr_);
575   
    }
575   
    }
576  
576  
577   
    run_wrapper(std::stop_token st, std::pmr::memory_resource* mr)
577   
    run_wrapper(std::stop_token st, std::pmr::memory_resource* mr)
578   
        requires (!InheritStopToken)
578   
        requires (!InheritStopToken)
579   
        : st_(std::move(st))
579   
        : st_(std::move(st))
580   
        , mr_(mr)
580   
        , mr_(mr)
581   
    {
581   
    {
582   
        set_current_frame_allocator(mr_);
582   
        set_current_frame_allocator(mr_);
583   
    }
583   
    }
584  
584  
585   
    // Non-copyable, non-movable (must be used immediately)
585   
    // Non-copyable, non-movable (must be used immediately)
586   
    run_wrapper(run_wrapper const&) = delete;
586   
    run_wrapper(run_wrapper const&) = delete;
587   
    run_wrapper(run_wrapper&&) = delete;
587   
    run_wrapper(run_wrapper&&) = delete;
588   
    run_wrapper& operator=(run_wrapper const&) = delete;
588   
    run_wrapper& operator=(run_wrapper const&) = delete;
589   
    run_wrapper& operator=(run_wrapper&&) = delete;
589   
    run_wrapper& operator=(run_wrapper&&) = delete;
590  
590  
591   
    template<IoRunnable Task>
591   
    template<IoRunnable Task>
592   
    [[nodiscard]] auto operator()(Task t) &&
592   
    [[nodiscard]] auto operator()(Task t) &&
593   
    {
593   
    {
594   
        if constexpr (InheritStopToken)
594   
        if constexpr (InheritStopToken)
595   
            return run_awaitable<Task, true, std::pmr::memory_resource*>{
595   
            return run_awaitable<Task, true, std::pmr::memory_resource*>{
596   
                mr_, std::move(t)};
596   
                mr_, std::move(t)};
597   
        else
597   
        else
598   
            return run_awaitable<Task, false, std::pmr::memory_resource*>{
598   
            return run_awaitable<Task, false, std::pmr::memory_resource*>{
599   
                mr_, std::move(t), std::move(st_)};
599   
                mr_, std::move(t), std::move(st_)};
600   
    }
600   
    }
601   
};
601   
};
602  
602  
603   
/// Specialization for stop_token only (no allocator).
603   
/// Specialization for stop_token only (no allocator).
604   
template<>
604   
template<>
605   
class [[nodiscard]] run_wrapper<false, void>
605   
class [[nodiscard]] run_wrapper<false, void>
606   
{
606   
{
607   
    std::stop_token st_;
607   
    std::stop_token st_;
608  
608  
609   
public:
609   
public:
610   
    explicit run_wrapper(std::stop_token st)
610   
    explicit run_wrapper(std::stop_token st)
611   
        : st_(std::move(st))
611   
        : st_(std::move(st))
612   
    {
612   
    {
613   
    }
613   
    }
614  
614  
615   
    // Non-copyable, non-movable (must be used immediately)
615   
    // Non-copyable, non-movable (must be used immediately)
616   
    run_wrapper(run_wrapper const&) = delete;
616   
    run_wrapper(run_wrapper const&) = delete;
617   
    run_wrapper(run_wrapper&&) = delete;
617   
    run_wrapper(run_wrapper&&) = delete;
618   
    run_wrapper& operator=(run_wrapper const&) = delete;
618   
    run_wrapper& operator=(run_wrapper const&) = delete;
619   
    run_wrapper& operator=(run_wrapper&&) = delete;
619   
    run_wrapper& operator=(run_wrapper&&) = delete;
620  
620  
621   
    template<IoRunnable Task>
621   
    template<IoRunnable Task>
622   
    [[nodiscard]] auto operator()(Task t) &&
622   
    [[nodiscard]] auto operator()(Task t) &&
623   
    {
623   
    {
624   
        return run_awaitable<Task, false, void>{std::move(t), std::move(st_)};
624   
        return run_awaitable<Task, false, void>{std::move(t), std::move(st_)};
625   
    }
625   
    }
626   
};
626   
};
627  
627  
628   
} // namespace boost::capy::detail
628   
} // namespace boost::capy::detail
629  
629  
630   
namespace boost::capy {
630   
namespace boost::capy {
631  
631  
632   
//----------------------------------------------------------
632   
//----------------------------------------------------------
633   
//
633   
//
634   
// run() overloads - with executor
634   
// run() overloads - with executor
635   
//
635   
//
636   
//----------------------------------------------------------
636   
//----------------------------------------------------------
637  
637  
638   
/** Bind a task to execute on a specific executor.
638   
/** Bind a task to execute on a specific executor.
639  
639  
640   
    Returns a wrapper that accepts a task and produces an awaitable.
640   
    Returns a wrapper that accepts a task and produces an awaitable.
641   
    When co_awaited, the task runs on the specified executor.
641   
    When co_awaited, the task runs on the specified executor.
642  
642  
643   
    @par Example
643   
    @par Example
644   
    @code
644   
    @code
645   
    co_await run(other_executor)(my_task());
645   
    co_await run(other_executor)(my_task());
646   
    @endcode
646   
    @endcode
647  
647  
648   
    @param ex The executor on which the task should run.
648   
    @param ex The executor on which the task should run.
649  
649  
650   
    @return A wrapper that accepts a task for execution.
650   
    @return A wrapper that accepts a task for execution.
651  
651  
652   
    @see task
652   
    @see task
653   
    @see executor
653   
    @see executor
654   
*/
654   
*/
655   
template<Executor Ex>
655   
template<Executor Ex>
656   
[[nodiscard]] auto
656   
[[nodiscard]] auto
657   
run(Ex ex)
657   
run(Ex ex)
658   
{
658   
{
659   
    return detail::run_wrapper_ex<Ex, true, void>{std::move(ex)};
659   
    return detail::run_wrapper_ex<Ex, true, void>{std::move(ex)};
660   
}
660   
}
661  
661  
662   
/** Bind a task to an executor with a stop token.
662   
/** Bind a task to an executor with a stop token.
663  
663  
664   
    @param ex The executor on which the task should run.
664   
    @param ex The executor on which the task should run.
665   
    @param st The stop token for cooperative cancellation.
665   
    @param st The stop token for cooperative cancellation.
666  
666  
667   
    @return A wrapper that accepts a task for execution.
667   
    @return A wrapper that accepts a task for execution.
668   
*/
668   
*/
669   
template<Executor Ex>
669   
template<Executor Ex>
670   
[[nodiscard]] auto
670   
[[nodiscard]] auto
671   
run(Ex ex, std::stop_token st)
671   
run(Ex ex, std::stop_token st)
672   
{
672   
{
673   
    return detail::run_wrapper_ex<Ex, false, void>{
673   
    return detail::run_wrapper_ex<Ex, false, void>{
674   
        std::move(ex), std::move(st)};
674   
        std::move(ex), std::move(st)};
675   
}
675   
}
676  
676  
677   
/** Bind a task to an executor with a memory resource.
677   
/** Bind a task to an executor with a memory resource.
678  
678  
679   
    @param ex The executor on which the task should run.
679   
    @param ex The executor on which the task should run.
680   
    @param mr The memory resource for frame allocation.
680   
    @param mr The memory resource for frame allocation.
681  
681  
682   
    @return A wrapper that accepts a task for execution.
682   
    @return A wrapper that accepts a task for execution.
683   
*/
683   
*/
684   
template<Executor Ex>
684   
template<Executor Ex>
685   
[[nodiscard]] auto
685   
[[nodiscard]] auto
686   
run(Ex ex, std::pmr::memory_resource* mr)
686   
run(Ex ex, std::pmr::memory_resource* mr)
687   
{
687   
{
688   
    return detail::run_wrapper_ex<Ex, true, std::pmr::memory_resource*>{
688   
    return detail::run_wrapper_ex<Ex, true, std::pmr::memory_resource*>{
689   
        std::move(ex), mr};
689   
        std::move(ex), mr};
690   
}
690   
}
691  
691  
692   
/** Bind a task to an executor with a standard allocator.
692   
/** Bind a task to an executor with a standard allocator.
693  
693  
694   
    @param ex The executor on which the task should run.
694   
    @param ex The executor on which the task should run.
695   
    @param alloc The allocator for frame allocation.
695   
    @param alloc The allocator for frame allocation.
696  
696  
697   
    @return A wrapper that accepts a task for execution.
697   
    @return A wrapper that accepts a task for execution.
698   
*/
698   
*/
699   
template<Executor Ex, detail::Allocator Alloc>
699   
template<Executor Ex, detail::Allocator Alloc>
700   
[[nodiscard]] auto
700   
[[nodiscard]] auto
701   
run(Ex ex, Alloc alloc)
701   
run(Ex ex, Alloc alloc)
702   
{
702   
{
703   
    return detail::run_wrapper_ex<Ex, true, Alloc>{
703   
    return detail::run_wrapper_ex<Ex, true, Alloc>{
704   
        std::move(ex), std::move(alloc)};
704   
        std::move(ex), std::move(alloc)};
705   
}
705   
}
706  
706  
707   
/** Bind a task to an executor with stop token and memory resource.
707   
/** Bind a task to an executor with stop token and memory resource.
708  
708  
709   
    @param ex The executor on which the task should run.
709   
    @param ex The executor on which the task should run.
710   
    @param st The stop token for cooperative cancellation.
710   
    @param st The stop token for cooperative cancellation.
711   
    @param mr The memory resource for frame allocation.
711   
    @param mr The memory resource for frame allocation.
712  
712  
713   
    @return A wrapper that accepts a task for execution.
713   
    @return A wrapper that accepts a task for execution.
714   
*/
714   
*/
715   
template<Executor Ex>
715   
template<Executor Ex>
716   
[[nodiscard]] auto
716   
[[nodiscard]] auto
717   
run(Ex ex, std::stop_token st, std::pmr::memory_resource* mr)
717   
run(Ex ex, std::stop_token st, std::pmr::memory_resource* mr)
718   
{
718   
{
719   
    return detail::run_wrapper_ex<Ex, false, std::pmr::memory_resource*>{
719   
    return detail::run_wrapper_ex<Ex, false, std::pmr::memory_resource*>{
720   
        std::move(ex), std::move(st), mr};
720   
        std::move(ex), std::move(st), mr};
721   
}
721   
}
722  
722  
723   
/** Bind a task to an executor with stop token and standard allocator.
723   
/** Bind a task to an executor with stop token and standard allocator.
724  
724  
725   
    @param ex The executor on which the task should run.
725   
    @param ex The executor on which the task should run.
726   
    @param st The stop token for cooperative cancellation.
726   
    @param st The stop token for cooperative cancellation.
727   
    @param alloc The allocator for frame allocation.
727   
    @param alloc The allocator for frame allocation.
728  
728  
729   
    @return A wrapper that accepts a task for execution.
729   
    @return A wrapper that accepts a task for execution.
730   
*/
730   
*/
731   
template<Executor Ex, detail::Allocator Alloc>
731   
template<Executor Ex, detail::Allocator Alloc>
732   
[[nodiscard]] auto
732   
[[nodiscard]] auto
733   
run(Ex ex, std::stop_token st, Alloc alloc)
733   
run(Ex ex, std::stop_token st, Alloc alloc)
734   
{
734   
{
735   
    return detail::run_wrapper_ex<Ex, false, Alloc>{
735   
    return detail::run_wrapper_ex<Ex, false, Alloc>{
736   
        std::move(ex), std::move(st), std::move(alloc)};
736   
        std::move(ex), std::move(st), std::move(alloc)};
737   
}
737   
}
738  
738  
739   
//----------------------------------------------------------
739   
//----------------------------------------------------------
740   
//
740   
//
741   
// run() overloads - no executor (inherits caller's)
741   
// run() overloads - no executor (inherits caller's)
742   
//
742   
//
743   
//----------------------------------------------------------
743   
//----------------------------------------------------------
744  
744  
745   
/** Run a task with a custom stop token.
745   
/** Run a task with a custom stop token.
746  
746  
747   
    The task inherits the caller's executor. Only the stop token
747   
    The task inherits the caller's executor. Only the stop token
748   
    is overridden.
748   
    is overridden.
749  
749  
750   
    @par Example
750   
    @par Example
751   
    @code
751   
    @code
752   
    std::stop_source source;
752   
    std::stop_source source;
753   
    co_await run(source.get_token())(cancellable_task());
753   
    co_await run(source.get_token())(cancellable_task());
754   
    @endcode
754   
    @endcode
755  
755  
756   
    @param st The stop token for cooperative cancellation.
756   
    @param st The stop token for cooperative cancellation.
757  
757  
758   
    @return A wrapper that accepts a task for execution.
758   
    @return A wrapper that accepts a task for execution.
759   
*/
759   
*/
760   
[[nodiscard]] inline auto
760   
[[nodiscard]] inline auto
761   
run(std::stop_token st)
761   
run(std::stop_token st)
762   
{
762   
{
763   
    return detail::run_wrapper<false, void>{std::move(st)};
763   
    return detail::run_wrapper<false, void>{std::move(st)};
764   
}
764   
}
765  
765  
766   
/** Run a task with a custom memory resource.
766   
/** Run a task with a custom memory resource.
767  
767  
768   
    The task inherits the caller's executor. The memory resource
768   
    The task inherits the caller's executor. The memory resource
769   
    is used for nested frame allocations.
769   
    is used for nested frame allocations.
770  
770  
771   
    @param mr The memory resource for frame allocation.
771   
    @param mr The memory resource for frame allocation.
772  
772  
773   
    @return A wrapper that accepts a task for execution.
773   
    @return A wrapper that accepts a task for execution.
774   
*/
774   
*/
775   
[[nodiscard]] inline auto
775   
[[nodiscard]] inline auto
776   
run(std::pmr::memory_resource* mr)
776   
run(std::pmr::memory_resource* mr)
777   
{
777   
{
778   
    return detail::run_wrapper<true, std::pmr::memory_resource*>{mr};
778   
    return detail::run_wrapper<true, std::pmr::memory_resource*>{mr};
779   
}
779   
}
780  
780  
781   
/** Run a task with a custom standard allocator.
781   
/** Run a task with a custom standard allocator.
782  
782  
783   
    The task inherits the caller's executor. The allocator is used
783   
    The task inherits the caller's executor. The allocator is used
784   
    for nested frame allocations.
784   
    for nested frame allocations.
785  
785  
786   
    @param alloc The allocator for frame allocation.
786   
    @param alloc The allocator for frame allocation.
787  
787  
788   
    @return A wrapper that accepts a task for execution.
788   
    @return A wrapper that accepts a task for execution.
789   
*/
789   
*/
790   
template<detail::Allocator Alloc>
790   
template<detail::Allocator Alloc>
791   
[[nodiscard]] auto
791   
[[nodiscard]] auto
792   
run(Alloc alloc)
792   
run(Alloc alloc)
793   
{
793   
{
794   
    return detail::run_wrapper<true, Alloc>{std::move(alloc)};
794   
    return detail::run_wrapper<true, Alloc>{std::move(alloc)};
795   
}
795   
}
796  
796  
797   
/** Run a task with stop token and memory resource.
797   
/** Run a task with stop token and memory resource.
798  
798  
799   
    The task inherits the caller's executor.
799   
    The task inherits the caller's executor.
800  
800  
801   
    @param st The stop token for cooperative cancellation.
801   
    @param st The stop token for cooperative cancellation.
802   
    @param mr The memory resource for frame allocation.
802   
    @param mr The memory resource for frame allocation.
803  
803  
804   
    @return A wrapper that accepts a task for execution.
804   
    @return A wrapper that accepts a task for execution.
805   
*/
805   
*/
806   
[[nodiscard]] inline auto
806   
[[nodiscard]] inline auto
807   
run(std::stop_token st, std::pmr::memory_resource* mr)
807   
run(std::stop_token st, std::pmr::memory_resource* mr)
808   
{
808   
{
809   
    return detail::run_wrapper<false, std::pmr::memory_resource*>{
809   
    return detail::run_wrapper<false, std::pmr::memory_resource*>{
810   
        std::move(st), mr};
810   
        std::move(st), mr};
811   
}
811   
}
812  
812  
813   
/** Run a task with stop token and standard allocator.
813   
/** Run a task with stop token and standard allocator.
814  
814  
815   
    The task inherits the caller's executor.
815   
    The task inherits the caller's executor.
816  
816  
817   
    @param st The stop token for cooperative cancellation.
817   
    @param st The stop token for cooperative cancellation.
818   
    @param alloc The allocator for frame allocation.
818   
    @param alloc The allocator for frame allocation.
819  
819  
820   
    @return A wrapper that accepts a task for execution.
820   
    @return A wrapper that accepts a task for execution.
821   
*/
821   
*/
822   
template<detail::Allocator Alloc>
822   
template<detail::Allocator Alloc>
823   
[[nodiscard]] auto
823   
[[nodiscard]] auto
824   
run(std::stop_token st, Alloc alloc)
824   
run(std::stop_token st, Alloc alloc)
825   
{
825   
{
826   
    return detail::run_wrapper<false, Alloc>{
826   
    return detail::run_wrapper<false, Alloc>{
827   
        std::move(st), std::move(alloc)};
827   
        std::move(st), std::move(alloc)};
828   
}
828   
}
829  
829  
830   
} // namespace boost::capy
830   
} // namespace boost::capy
831  
831  
832   
#endif
832   
#endif