add nothrow_tag_invokable concept

- update as_exception_ptr_test
facebookexperimental · Apr 15, 2021 · aca13cb · aca13cb
1 parent e4cc6f6
commit aca13cb
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Showing 3 changed files with 10 additions and 6 deletions.
diff --git a/include/unifex/as_exception_ptr.hpp b/include/unifex/as_exception_ptr.hpp
@@ -35,17 +35,17 @@ namespace unifex
       }
 
       // convert std::exception based types to std::exception_ptr
-      template(typename Exception)(requires std::is_base_of_v<std::exception, Exception>)
-          std::exception_ptr
-          operator()(Exception&& ex) const noexcept {
+      template(typename Exception)
+          (requires std::is_base_of_v<std::exception, Exception>)
+      std::exception_ptr operator()(Exception&& ex) const noexcept {
         return make_exception_ptr(std::forward<Exception>(ex));
       }
 
       // use customization point
       // to resolve ErrorCode -> std::exception_ptr conversion
       template(typename ErrorCode)
-          (requires tag_invocable<_fn, ErrorCode>) std::exception_ptr
-      operator()(ErrorCode&& error) const noexcept {
+          (requires nothrow_tag_invocable<_fn, ErrorCode>)
+      std::exception_ptr operator()(ErrorCode&& error) const noexcept {
         return tag_invoke(*this, std::forward<ErrorCode>(error));
       }
     } as_exception_ptr{};

diff --git a/include/unifex/tag_invoke.hpp b/include/unifex/tag_invoke.hpp
@@ -104,6 +104,10 @@ namespace unifex {
       (sizeof(_tag_invoke::try_tag_invoke<CPO, Args...>(0)) ==
        sizeof(_tag_invoke::yes_type));
 
+  template <typename CPO, typename... Args>
+  UNIFEX_CONCEPT nothrow_tag_invocable =
+      (tag_invocable<CPO, Args...> && is_nothrow_tag_invocable_v<CPO, Args...>);
+
   template <typename Fn>
   using meta_tag_invoke_result =
       meta_quote1_<tag_invoke_result_t>::bind_front<Fn>;

diff --git a/test/as_exception_ptr_test.cpp b/test/as_exception_ptr_test.cpp
@@ -34,7 +34,7 @@ struct test_error {
   int error_code;
 };
 
-std::exception_ptr tag_invoke(tag_t<as_exception_ptr>, test_error&& error) {
+std::exception_ptr tag_invoke(tag_t<as_exception_ptr>, test_error&& error) noexcept {
   return std::make_exception_ptr(
       std::runtime_error(std::to_string(std::forward<test_error>(error).error_code)));
 }