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tkoeppe merged 1 commit into from
Apr 20, 2026
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LWG Motion 38: P4154R0 Renaming various execution things #8959

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92 changes: 46 additions & 46 deletions source/exec.tex
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Original file line number Diff line number Diff line change
Expand Up @@ -498,13 +498,13 @@
struct default_domain;

// \ref{exec.sched}, schedulers
struct @\libglobal{scheduler_t}@ {};
struct @\libglobal{scheduler_tag}@ {};

template<class Sch>
concept @\libconcept{scheduler}@ = @\seebelow@;

// \ref{exec.recv}, receivers
struct @\libglobal{receiver_t}@ {};
struct @\libglobal{receiver_tag}@ {};

template<class Rcvr>
concept @\libconcept{receiver}@ = @\seebelow@;
Expand All @@ -524,7 +524,7 @@
inline constexpr set_stopped_t @\libglobal{set_stopped}@{};

// \ref{exec.opstate}, operation states
struct @\libglobal{operation_state_t}@ {};
struct @\libglobal{operation_state_tag}@ {};

template<class O>
concept @\libconcept{operation_state}@ = @\seebelow@;
Expand All @@ -533,7 +533,7 @@
inline constexpr start_t @\libglobal{start}@{};

// \ref{exec.snd}, senders
struct @\libglobal{sender_t}@ {};
struct @\libglobal{sender_tag}@ {};

template<class Sndr>
inline constexpr bool enable_sender = @\seebelow@;
Expand Down Expand Up @@ -756,8 +756,8 @@
class @\libglobal{parallel_scheduler}@;
parallel_scheduler get_parallel_scheduler();

// \ref{exec.sysctxrepl}, namespace \tcode{system_context_replaceability}
namespace @\libglobal{system_context_replaceability}@ {
// \ref{exec.parschedrepl}, namespace \tcode{parallel_scheduler_replacement}
namespace @\libglobal{parallel_scheduler_replacement}@ {
struct receiver_proxy;
struct bulk_item_receiver_proxy;
struct parallel_scheduler_backend;
Expand Down Expand Up @@ -1265,7 +1265,7 @@
namespace std::execution {
template<class Sch>
concept @\deflibconcept{scheduler}@ =
@\libconcept{derived_from}@<typename remove_cvref_t<Sch>::scheduler_concept, scheduler_t> &&
@\libconcept{derived_from}@<typename remove_cvref_t<Sch>::scheduler_concept, scheduler_tag> &&
@\exposconcept{queryable}@<Sch> &&
requires(Sch&& sch) {
{ schedule(std::forward<Sch>(sch)) } -> @\libconcept{sender}@;
Expand Down Expand Up @@ -1367,7 +1367,7 @@
namespace std::execution {
template<class Rcvr>
concept @\deflibconcept{receiver}@ =
@\libconcept{derived_from}@<typename remove_cvref_t<Rcvr>::receiver_concept, receiver_t> &&
@\libconcept{derived_from}@<typename remove_cvref_t<Rcvr>::receiver_concept, receiver_tag> &&
requires(const remove_cvref_t<Rcvr>& rcvr) {
{ get_env(rcvr) } -> @\exposconcept{queryable}@;
} &&
Expand Down Expand Up @@ -1562,7 +1562,7 @@
namespace std::execution {
template<class O>
concept @\deflibconcept{operation_state}@ =
@\libconcept{derived_from}@<typename O::operation_state_concept, operation_state_t> &&
@\libconcept{derived_from}@<typename O::operation_state_concept, operation_state_tag> &&
requires (O& o) {
start(o);
};
Expand Down Expand Up @@ -2069,7 +2069,7 @@
template<class Sndr, class Rcvr, class Index>
requires @\exposconcept{valid-specialization}@<@\exposid{env-type}@, Index, Sndr, Rcvr>
struct @\exposidnc{basic-receiver}@ { // \expos
using receiver_concept = receiver_t;
using receiver_concept = receiver_tag;

using @\exposidnc{tag-t}@ = tag_of_t<Sndr>; // \expos
using @\exposidnc{state-t}@ = @\exposidnc{state-type}@<Sndr, Rcvr>; // \expos
Expand Down Expand Up @@ -2141,7 +2141,7 @@
requires @\exposconcept{valid-specialization}@<@\exposid{state-type}@, Sndr, Rcvr> &&
@\exposconcept{valid-specialization}@<@\exposid{connect-all-result}@, Sndr, Rcvr>
struct @\exposidnc{basic-operation}@ : @\exposidnc{basic-state}@<Sndr, Rcvr> { // \expos
using operation_state_concept = operation_state_t;
using operation_state_concept = operation_state_tag;
using @\exposidnc{tag-t}@ = tag_of_t<Sndr>; // \expos

@\exposidnc{connect-all-result}@<Sndr, Rcvr> @\exposidnc{inner-ops}@; // \expos
Expand Down Expand Up @@ -2265,7 +2265,7 @@
namespace std::execution {
template<class Tag, class Data, class... Child>
struct @\exposidnc{basic-sender}@ : @\exposidnc{product-type}@<Tag, Data, Child...> { // \expos
using sender_concept = sender_t;
using sender_concept = sender_tag;
using @\exposidnc{indices-for}@ = index_sequence_for<Child...>; // \expos

decltype(auto) get_env() const noexcept {
Expand Down Expand Up @@ -2360,7 +2360,7 @@
%%FIXME: Should this be in a namespace?
\begin{codeblock}
struct @\exposid{not-a-sender}@ {
using sender_concept = sender_t;
using sender_concept = sender_tag;

template<class Sndr>
static consteval auto get_completion_signatures() -> completion_signatures<> {
Expand All @@ -2374,7 +2374,7 @@
\indexlibrarymember{schedule}{\exposid{not-a-sender}}%
\begin{codeblock}
struct @\exposid{not-a-scheduler}@ {
using scheduler_concept = scheduler_t;
using scheduler_concept = scheduler_tag;

constexpr auto schedule() const noexcept {
return @\exposid{not-a-sender}@();
Expand Down Expand Up @@ -2493,7 +2493,7 @@

template<class Sndr>
concept @\defexposconcept{is-sender}@ = // \expos
@\libconcept{derived_from}@<typename Sndr::sender_concept, sender_t>;
@\libconcept{derived_from}@<typename Sndr::sender_concept, sender_tag>;

template<class Sndr>
concept @\defexposconcept{enable-sender}@ = // \expos
Expand Down Expand Up @@ -3154,7 +3154,7 @@
\begin{codeblock}
namespace std::execution {
struct @\exposid{operation-state-task}@ { // \expos
using operation_state_concept = operation_state_t;
using operation_state_concept = operation_state_tag;
using promise_type = @\exposid{connect-awaitable-promise}@;

explicit @\exposid{operation-state-task}@(coroutine_handle<> h) noexcept : coro(h) {}
Expand Down Expand Up @@ -3766,7 +3766,7 @@
\begin{codeblock}
namespace std::execution {
struct @\exposid{receiver-type}@ {
using receiver_concept = receiver_t;
using receiver_concept = receiver_tag;
@\exposid{state-type}@* @\exposid{state}@; // \expos

void set_value() && noexcept {
Expand Down Expand Up @@ -4174,7 +4174,7 @@
namespace std::execution {
template<class Rcvr, class Env>
struct @\exposid{receiver2}@ {
using receiver_concept = receiver_t;
using receiver_concept = receiver_tag;

template<class... Args>
void set_value(Args&&... args) && noexcept {
Expand Down Expand Up @@ -4295,7 +4295,7 @@
@\exposid{let-state}@& state; // \expos
Rcvr& @\exposid{rcvr}@; // \expos

using receiver_concept = receiver_t;
using receiver_concept = receiver_tag;

template<class... Args>
constexpr void set_value(Args&&... args) noexcept {
Expand Down Expand Up @@ -5584,7 +5584,7 @@
namespace std::execution {
template<class Completions>
struct @\exposid{spawn-future-receiver}@ { // \expos
using receiver_concept = receiver_t;
using receiver_concept = receiver_tag;

@\exposid{spawn-future-state-base}@<Completions>* @\exposid{state}@; // \expos

Expand Down Expand Up @@ -5858,7 +5858,7 @@
stop_callback_for_t<@\exposid{stop-token-t}@, @\exposid{callback}@>;

struct @\exposid{rcvr-t}@ { // \expos
using receiver_concept = receiver_t;
using receiver_concept = receiver_tag;
@\exposid{future-operation}@* @\exposid{op}@; // \expos

template<class... T>
Expand Down Expand Up @@ -6091,7 +6091,7 @@

template<class Sndr>
struct @\exposid{sync-wait-receiver}@ { // \expos
using receiver_concept = execution::receiver_t;
using receiver_concept = execution::receiver_tag;
@\exposidnc{sync-wait-state}@<Sndr>* @\exposid{state}@; // \expos

template<class... Args>
Expand Down Expand Up @@ -6301,7 +6301,7 @@
\begin{codeblock}
namespace std::execution {
struct @\exposid{spawn-receiver}@ { // \expos
using receiver_concept = receiver_t;
using receiver_concept = receiver_tag;

@\exposid{spawn-state-base}@* @\exposid{state}@; // \expos
void set_value() && noexcept { @\exposid{state}@->@\exposid{complete}@(); }
Expand Down Expand Up @@ -6435,7 +6435,7 @@
\begin{example}
\begin{codeblock}
struct my_sender {
using sender_concept = sender_t;
using sender_concept = sender_tag;
using completion_signatures =
execution::completion_signatures<
set_value_t(),
Expand Down Expand Up @@ -7075,7 +7075,7 @@
\exposid{awaitable-receiver} is equivalent to:
\begin{codeblock}
struct @\exposid{awaitable-receiver}@ {
using receiver_concept = receiver_t;
using receiver_concept = receiver_tag;
variant<monostate, @\exposidnc{result-type}@, exception_ptr>* @\exposidnc{result-ptr}@; // \expos
coroutine_handle<Promise> @\exposidnc{continuation}@; // \expos
// \seebelow
Expand Down Expand Up @@ -7395,7 +7395,7 @@
class @\exposidnc{inline-state}@; // \expos

public:
using scheduler_concept = scheduler_t;
using scheduler_concept = scheduler_tag;

constexpr @\exposid{inline-sender}@ schedule() noexcept { return {}; }
constexpr bool operator==(const inline_scheduler&) const noexcept = default;
Expand Down Expand Up @@ -7453,7 +7453,7 @@
class @\exposid{backend-for}@; // \expos

public:
using scheduler_concept = scheduler_t;
using scheduler_concept = scheduler_tag;

template<class Sch, class Allocator = allocator<void>>
requires (!@\libconcept{same_as}@<task_scheduler, remove_cvref_t<Sch>>) && @\libconcept{scheduler}@<Sch>
Expand All @@ -7470,8 +7470,8 @@
friend bool operator==(const task_scheduler& lhs, const Sch& rhs) noexcept;

private:
// see \ref{exec.sysctxrepl.psb}
shared_ptr<system_context_replaceability::parallel_scheduler_backend> @\exposidnc{sch_}@; // \expos
// see \ref{exec.parschedrepl.psb}
shared_ptr<parallel_scheduler_replacement::parallel_scheduler_backend> @\exposidnc{sch_}@; // \expos
};
}
\end{codeblock}
Expand Down Expand Up @@ -7550,7 +7550,7 @@
namespace std::execution {
template<@\libconcept{scheduler}@ Sch>
class task_scheduler::@\exposid{backend-for}@
: public system_context_replaceability::parallel_scheduler_backend { // \expos
: public parallel_scheduler_replacement::parallel_scheduler_backend { // \expos
public:
explicit @\exposid{backend-for}@(Sch sch) : @\exposid{sched_}@(std::move(sch)) {}

Expand Down Expand Up @@ -7648,7 +7648,7 @@
\begin{itemize}
\item
\tcode{r} is a proxy for \tcode{rcvr} with base
\tcode{system_context_replaceability::receiver_proxy}\iref{exec.par.scheduler}
\tcode{parallel_scheduler_replacement::receiver_proxy}\iref{exec.par.scheduler}
and
\item
\tcode{s} is a preallocated backend storage for \tcode{r}.
Expand Down Expand Up @@ -7767,7 +7767,7 @@
class @\exposidnc{state}@; // \expos

public:
using sender_concept = sender_t;
using sender_concept = sender_tag;
using allocator_type = @\seebelow@;
using start_scheduler_type = @\seebelow@;
using stop_source_type = @\seebelow@;
Expand Down Expand Up @@ -7915,7 +7915,7 @@
template<@\libconcept{receiver}@ Rcvr>
class task<T, Environment>::@\exposidnc{state}@ { // \expos
public:
using operation_state_concept = operation_state_t;
using operation_state_concept = operation_state_tag;

template<class R>
@\exposid{state}@(coroutine_handle<promise_type> h, R&& rr);
Expand Down Expand Up @@ -8530,7 +8530,7 @@
template<class Scope, class Rcvr>
struct @\exposid{state}@ { // \expos
struct @\exposid{rcvr-t}@ { // \expos
using receiver_concept = receiver_t;
using receiver_concept = receiver_tag;

Rcvr& @\exposid{rcvr}@; // \expos

Expand Down Expand Up @@ -9057,7 +9057,7 @@
\begin{itemize}
\item
\tcode{r} is a proxy for \tcode{rcvr}
with base \tcode{system_context_replaceability::receiver_proxy} and
with base \tcode{parallel_scheduler_replacement::receiver_proxy} and
\item
\tcode{s} is a preallocated backend storage for \tcode{r}.
\end{itemize}
Expand Down Expand Up @@ -9120,7 +9120,7 @@
\begin{itemize}
\item
\tcode{r} is a proxy for \tcode{rcvr}
with base \tcode{system_context_replaceability::bulk_item_receiver_proxy}
with base \tcode{parallel_scheduler_replacement::bulk_item_receiver_proxy}
such that \tcode{r.execute(i, j)} for indices \tcode{i} and \tcode{j}
has effects equivalent to
\tcode{f(i, j, args...)} if \tcode{p} is true and
Expand All @@ -9145,7 +9145,7 @@
\begin{itemize}
\item
\tcode{r} is a proxy for \tcode{rcvr}
with base \tcode{system_context_replaceability::bulk_item_receiver_proxy}
with base \tcode{parallel_scheduler_replacement::bulk_item_receiver_proxy}
such that \tcode{r.execute(i, i + 1)} for index \tcode{i}
has effects equivalent to
\tcode{f(i, args...)} if \tcode{p} is true and
Expand All @@ -9168,25 +9168,25 @@
\begin{itemdescr}
\pnum
\effects
Let \tcode{eb} be the result of \tcode{system_context_replaceability::query_parallel_scheduler_backend()}.
Let \tcode{eb} be the result of \tcode{parallel_scheduler_replacement::query_parallel_scheduler_backend()}.
If \tcode{eb == nullptr} is \tcode{true},
calls \tcode{terminate}\iref{except.terminate}.
Otherwise, returns a \tcode{parallel_scheduler} object
associated with \tcode{eb}.
\end{itemdescr}

\rSec1[exec.sysctxrepl]{Namespace \tcode{system_context_replaceability}}
\rSec1[exec.parschedrepl]{Namespace \tcode{parallel_scheduler_replacement}}

\rSec2[exec.sysctxrepl.general]{General}
\rSec2[exec.parschedrepl.general]{General}

\pnum
Facilities in the \tcode{system_context_replaceability} namespace
Facilities in the \tcode{parallel_scheduler_replacement} namespace
allow users to replace the default implementation of \tcode{parallel_scheduler}.

\rSec2[exec.sysctxrepl.recvproxy]{Receiver proxies}
\rSec2[exec.parschedrepl.recvproxy]{Receiver proxies}

\begin{codeblock}
namespace std::execution::system_context_replaceability {
namespace std::execution::parallel_scheduler_replacement {
struct @\libglobal{receiver_proxy}@ {
protected:
virtual bool @\exposidnc{query-env}@(@\unspecnc@) noexcept = 0; // \expos
Expand Down Expand Up @@ -9270,7 +9270,7 @@
all calls to \tcode{try_query} return equivalent \tcode{inplace_stop_token} objects.
\end{itemdescr}

\rSec2[exec.sysctxrepl.query]{\tcode{query_parallel_scheduler_backend}}
\rSec2[exec.parschedrepl.query]{\tcode{query_parallel_scheduler_backend}}

\indexlibraryglobal{query_parallel_scheduler_backend}%
\begin{itemdecl}
Expand All @@ -9297,10 +9297,10 @@
This function is replaceable\iref{term.replaceable.function}.
\end{itemdescr}

\rSec2[exec.sysctxrepl.psb]{Class \tcode{parallel_scheduler_backend}}
\rSec2[exec.parschedrepl.psb]{Class \tcode{parallel_scheduler_backend}}

\begin{codeblock}
namespace std::execution::system_context_replaceability {
namespace std::execution::parallel_scheduler_replacement {
struct @\libglobal{parallel_scheduler_backend}@ {
virtual ~parallel_scheduler_backend() = default;

Expand Down
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