NVIDIA · ericniebler · Feb 23, 2026 · Feb 24, 2026
diff --git a/examples/benchmark/static_thread_pool_bulk_enqueue.cpp b/examples/benchmark/static_thread_pool_bulk_enqueue.cpp
@@ -17,7 +17,7 @@
 #include "./common.hpp"
 #include <exec/static_thread_pool.hpp>
 
-#if STDEXEC_HAS_STD_RANGES()
+#if !STDEXEC_NO_STDCPP_RANGES()
 #  include <exec/sequence/ignore_all_values.hpp>
 #  include <ranges>
 

diff --git a/examples/benchmark/static_thread_pool_bulk_enqueue_nested.cpp b/examples/benchmark/static_thread_pool_bulk_enqueue_nested.cpp
@@ -17,7 +17,7 @@
 #include "./common.hpp"
 #include <exec/static_thread_pool.hpp>
 
-#if STDEXEC_HAS_STD_RANGES()
+#if !STDEXEC_NO_STDCPP_RANGES()
 #  include <exec/sequence/ignore_all_values.hpp>
 #  include <ranges>
 

diff --git a/examples/hello_coro.cpp b/examples/hello_coro.cpp
@@ -18,7 +18,7 @@
 // Pull in the reference implementation of P2300:
 #include <stdexec/execution.hpp>
 
-#if !STDEXEC_NO_STD_COROUTINES() && !STDEXEC_NVHPC()
+#if !STDEXEC_NO_STDCPP_COROUTINES() && !STDEXEC_NVHPC()
 #  include <exec/task.hpp>
 
 using namespace stdexec;

diff --git a/examples/nvexec/maxwell/stdpar.cuh b/examples/nvexec/maxwell/stdpar.cuh
@@ -20,7 +20,7 @@
 
 #include "common.cuh"  // IWYU pragma: keep
 
-#if STDEXEC_HAS_PARALLEL_ALGORITHMS()
+#if !STDEXEC_NO_STDCPP_PARALLEL_ALGORITHMS()
 
 #  if STDEXEC_CUDA_COMPILATION()
 #    include "../include/nvexec/detail/throw_on_cuda_error.cuh"
@@ -81,4 +81,4 @@ void run_stdpar(float            dt,
                      });
 }
 
-#endif
+#endif  // !STDEXEC_NO_STDCPP_PARALLEL_ALGORITHMS()
diff --git a/examples/nvexec/maxwell_cpu_mt.cu b/examples/nvexec/maxwell_cpu_mt.cu
@@ -35,7 +35,7 @@ auto main(int argc, char *argv[]) -> int
               << "\t--write-vtk\n"
               << "\t--iterations\n"
               << "\t--run-std\n"
-              << (STDEXEC_HAS_PARALLEL_ALGORITHMS() ? "\t--run-stdpar\n" : "")
+              << (STDEXEC_NO_STDCPP_PARALLEL_ALGORITHMS() ? "" : "\t--run-stdpar\n")
               << "\t--run-thread-pool-scheduler\n"
               << "\t--N\n"
               << std::endl;
@@ -79,7 +79,7 @@ auto main(int argc, char *argv[]) -> int
     run_std(dt, write_vtk, n_iterations, grid, "CPU (std)");
   }
 
-#  if STDEXEC_HAS_PARALLEL_ALGORITHMS()
+#  if !STDEXEC_NO_STDCPP_PARALLEL_ALGORITHMS()
   if (value(params, "run-stdpar"))
   {
     bool const       gpu    = is_gpu_policy(stdexec::par_unseq);

diff --git a/examples/nvexec/maxwell_gpu_s.cu b/examples/nvexec/maxwell_gpu_s.cu
@@ -30,7 +30,7 @@ auto main(int argc, char *argv[]) -> int
     std::cout << "Usage: " << argv[0] << " [OPTION]...\n"
               << "\t--write-vtk\n"
               << "\t--iterations\n"
-              << (STDEXEC_HAS_PARALLEL_ALGORITHMS() ? "\t--run-stdpar\n" : "")  //
+              << (STDEXEC_NO_STDCPP_PARALLEL_ALGORITHMS() ? "" : "\t--run-stdpar\n")  //
               << "\t--run-cuda\n"
               << "\t--run-stream-scheduler\n"
               << "\t--N\n"
@@ -75,7 +75,7 @@ auto main(int argc, char *argv[]) -> int
     run_snr_on("GPU (snr cuda stream)", stream_ctx.get_scheduler());
   }
 
-#  if STDEXEC_HAS_PARALLEL_ALGORITHMS()
+#  if !STDEXEC_NO_STDCPP_PARALLEL_ALGORITHMS()
   if (value(params, "run-stdpar"))
   {
     bool const       gpu    = is_gpu_policy(stdexec::par_unseq);
@@ -87,7 +87,7 @@ auto main(int argc, char *argv[]) -> int
 
     run_stdpar(dt, write_vtk, n_iterations, grid, stdexec::par_unseq, method);
   }
-#  endif  // STDEXEC_HAS_PARALLEL_ALGORITHMS()
+#  endif  // !STDEXEC_NO_STDCPP_PARALLEL_ALGORITHMS()
 }
 
 #endif  // !defined(STDEXEC_CLANGD_INVOKED)
diff --git a/examples/server_theme/let_value.cpp b/examples/server_theme/let_value.cpp
@@ -52,7 +52,7 @@
 #include "exec/start_detached.hpp"
 #include "exec/static_thread_pool.hpp"
 
-#if !STDEXEC_NO_STD_EXCEPTIONS()
+#if !STDEXEC_NO_STDCPP_EXCEPTIONS()
 namespace ex = stdexec;
 
 struct http_request
@@ -177,4 +177,4 @@ int main()
   std::cout << "This example requires C++ exceptions to be enabled.\n";
   return 0;
 }
-#endif  // !STDEXEC_NO_STD_EXCEPTIONS()
+#endif  // !STDEXEC_NO_STDCPP_EXCEPTIONS()
diff --git a/include/exec/detail/bit_cast.hpp b/include/exec/detail/bit_cast.hpp
@@ -21,19 +21,20 @@
 #if __has_include(<bit>)
 #  include <bit>
 #  if __cpp_lib_bit_cast >= 2018'06L
-#    define STDEXEC_HAS_BIT_CAST
+#    define STDEXEC_NO_STDCPP_BIT_CAST() 0
+#  else
+#    define STDEXEC_NO_STDCPP_BIT_CAST() 1
 #  endif
 #endif
 
 #include <cstring>
 
 namespace experimental::execution
 {
-
   template <class _Ty>
   concept __trivially_copyable = STDEXEC_IS_TRIVIALLY_COPYABLE(_Ty);
 
-#if defined(STDEXEC_HAS_BIT_CAST)
+#if !STDEXEC_NO_STDCPP_BIT_CAST()
   using std::bit_cast;
 #else
   template <__trivially_copyable _To, __trivially_copyable _From>

diff --git a/include/exec/sequence/iterate.hpp b/include/exec/sequence/iterate.hpp
@@ -18,7 +18,7 @@
 
 #include "../../stdexec/__detail/__config.hpp"
 
-#if STDEXEC_HAS_STD_RANGES()
+#if !STDEXEC_NO_STDCPP_RANGES()
 
 #  include "../../stdexec/__detail/__optional.hpp"
 #  include "../../stdexec/execution.hpp"
@@ -241,4 +241,4 @@ namespace experimental::execution
 
 namespace exec = experimental::execution;
 
-#endif  // STDEXEC_HAS_STD_RANGES()
+#endif  // !STDEXEC_NO_STDCPP_RANGES()
diff --git a/include/exec/sequence_senders.hpp b/include/exec/sequence_senders.hpp
@@ -245,7 +245,7 @@ namespace experimental::execution
   struct _FAILED_TO_COMPUTE_SEQUENCE_ITEM_TYPES_
   {};
 
-#if STDEXEC_NO_STD_CONSTEXPR_EXCEPTIONS()
+#if STDEXEC_NO_STDCPP_CONSTEXPR_EXCEPTIONS()
 
   template <class... _What, class... _Values>
   [[nodiscard]]

diff --git a/include/exec/static_thread_pool.hpp b/include/exec/static_thread_pool.hpp
@@ -89,7 +89,7 @@ namespace experimental::execution
       return std::make_pair(static_cast<Shape>(begin), static_cast<Shape>(end));
     }
 
-#if STDEXEC_HAS_STD_RANGES()
+#if !STDEXEC_NO_STDCPP_RANGES()
     namespace schedule_all_
     {
       template <class Range>
@@ -252,7 +252,7 @@ namespace experimental::execution
         _static_thread_pool& pool_;
       };
 
-#if STDEXEC_HAS_STD_RANGES()
+#if !STDEXEC_NO_STDCPP_RANGES()
       struct _transform_iterate
       {
         template <class Range>
@@ -300,7 +300,7 @@ namespace experimental::execution
           }
         }
 
-#if STDEXEC_HAS_STD_RANGES()
+#if !STDEXEC_NO_STDCPP_RANGES()
         template <sender_expr_for<exec::iterate_t> Sender, class Env>
         constexpr auto
         transform_sender(STDEXEC::set_value_t, Sender&& sndr, const Env& env) const noexcept
@@ -1564,7 +1564,7 @@ namespace experimental::execution
       {}
     };
 
-#if STDEXEC_HAS_STD_RANGES()
+#if !STDEXEC_NO_STDCPP_RANGES()
     namespace schedule_all_
     {
       template <class Rcvr>
@@ -1823,7 +1823,7 @@ namespace experimental::execution
 
   struct static_thread_pool : private _pool_::_static_thread_pool
   {
-#if STDEXEC_HAS_STD_RANGES()
+#if !STDEXEC_NO_STDCPP_RANGES()
     friend struct _pool_::schedule_all_t;
 #endif
     using task_base = _pool_::task_base;
@@ -1858,7 +1858,7 @@ namespace experimental::execution
     using _pool_::_static_thread_pool::params;
   };
 
-#if STDEXEC_HAS_STD_RANGES()
+#if !STDEXEC_NO_STDCPP_RANGES()
   namespace _pool_
   {
     struct schedule_all_t

diff --git a/include/stdexec/__detail/__as_awaitable.hpp b/include/stdexec/__detail/__as_awaitable.hpp
@@ -31,7 +31,7 @@
 
 namespace STDEXEC
 {
-#if !STDEXEC_NO_STD_COROUTINES()
+#if !STDEXEC_NO_STDCPP_COROUTINES()
   namespace __detail
   {
     template <std::size_t _Count>

diff --git a/include/stdexec/__detail/__awaitable.hpp b/include/stdexec/__detail/__awaitable.hpp
@@ -21,7 +21,7 @@
 
 namespace STDEXEC
 {
-#if !STDEXEC_NO_STD_COROUTINES()
+#if !STDEXEC_NO_STDCPP_COROUTINES()
   // Define some concepts and utilities for working with awaitables
   template <class _Tp>
   concept __await_suspend_result = __one_of<_Tp, void, bool>

diff --git a/include/stdexec/__detail/__completion_signatures.hpp b/include/stdexec/__detail/__completion_signatures.hpp
@@ -77,7 +77,7 @@ namespace STDEXEC
   using __completion_signature_ptrs_t = decltype(__cmplsigs::__repack_completions(
     static_cast<_SigPtrs>(nullptr)...));
 
-#if STDEXEC_NO_STD_CONSTEXPR_EXCEPTIONS()
+#if STDEXEC_NO_STDCPP_CONSTEXPR_EXCEPTIONS()
 
   template <class, class... _What, class... _Values>
   [[nodiscard]]
@@ -561,7 +561,7 @@ namespace STDEXEC
   //   }
   //   else
 
-#if STDEXEC_NO_STD_CONSTEXPR_EXCEPTIONS()
+#if STDEXEC_NO_STDCPP_CONSTEXPR_EXCEPTIONS()
 
 #  define STDEXEC_COMPLSIGS_LET(_ID, ...)                                                          \
     if constexpr ([[maybe_unused]]                                                                 \

diff --git a/include/stdexec/__detail/__concepts.hpp b/include/stdexec/__detail/__concepts.hpp
@@ -25,14 +25,7 @@
 #include <utility>  // IWYU pragma: keep for std::swap
 #include <version>
 
-// Perhaps the stdlib lacks support for concepts though:
-#if __has_include(<concepts>) && __cpp_lib_concepts >= 2020'02L
-#  define STDEXEC_HAS_STD_CONCEPTS_HEADER() 1
-#else
-#  define STDEXEC_HAS_STD_CONCEPTS_HEADER() 0
-#endif
-
-#if STDEXEC_HAS_STD_CONCEPTS_HEADER()
+#if !STDEXEC_NO_STDCPP_CONCEPTS_HEADER()
 #  include <concepts>
 #else
 #  include <type_traits>
@@ -112,7 +105,7 @@ namespace STDEXEC
     template <class _Ap, class _Bp>
     concept same_as = __same_as<_Ap, _Bp> && __same_as<_Bp, _Ap>;
 
-#if STDEXEC_HAS_STD_CONCEPTS_HEADER()
+#if !STDEXEC_NO_STDCPP_CONCEPTS_HEADER()
 
     using std::integral;
     using std::derived_from;