[committed] libstdc++: Define std::invoke_r for C++23 (P2136R3)
Jonathan Wakely
jwakely@redhat.com
Thu Sep 2 17:52:23 GMT 2021
We already supported this feature as std::__invoke<R>, for internal use.
This just adds a public version of it to <functional>.
Internal uses should continue to include <bits/invoke.h> and use
std::__invoke<R> so that they don't need to include all of <functional>.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/std/functional (invoke_r): Define.
* include/std/version (__cpp_lib_invoke_r): Define.
* testsuite/20_util/function_objects/invoke/version.cc: Check
for __cpp_lib_invoke_r as well as __cpp_lib_invoke.
* testsuite/20_util/function_objects/invoke/4.cc: New test.
Tested x86_64-linux. Committed to trunk.
-------------- next part --------------
commit 5b73abd1a5f44f72e36bc7aefd423816083291ea
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Thu Sep 2 11:54:12 2021
libstdc++: Define std::invoke_r for C++23 (P2136R3)
We already supported this feature as std::__invoke<R>, for internal use.
This just adds a public version of it to <functional>.
Internal uses should continue to include <bits/invoke.h> and use
std::__invoke<R> so that they don't need to include all of <functional>.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/std/functional (invoke_r): Define.
* include/std/version (__cpp_lib_invoke_r): Define.
* testsuite/20_util/function_objects/invoke/version.cc: Check
for __cpp_lib_invoke_r as well as __cpp_lib_invoke.
* testsuite/20_util/function_objects/invoke/4.cc: New test.
diff --git a/libstdc++-v3/include/std/functional b/libstdc++-v3/include/std/functional
index 131e6629341..0b257926fd5 100644
--- a/libstdc++-v3/include/std/functional
+++ b/libstdc++-v3/include/std/functional
@@ -96,6 +96,21 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return std::__invoke(std::forward<_Callable>(__fn),
std::forward<_Args>(__args)...);
}
+
+#if __cplusplus > 202002L
+# define __cpp_lib_invoke_r 202106L
+
+ /// Invoke a callable object and convert the result to _Res.
+ template<typename _Res, typename _Callable, typename... _Args>
+ requires is_invocable_r_v<_Res, _Callable, _Args...>
+ constexpr _Res
+ invoke_r(_Callable&& __fn, _Args&&... __args)
+ noexcept(is_nothrow_invocable_r_v<_Res, _Callable, _Args...>)
+ {
+ return std::__invoke_r<_Res>(std::forward<_Callable>(__fn),
+ std::forward<_Args>(__args)...);
+ }
+#endif // C++23
#endif // C++17
template<typename _MemFunPtr,
diff --git a/libstdc++-v3/include/std/version b/libstdc++-v3/include/std/version
index 70d573bb517..f950bf0f0db 100644
--- a/libstdc++-v3/include/std/version
+++ b/libstdc++-v3/include/std/version
@@ -278,6 +278,7 @@
#if __cplusplus > 202002L
// c++2b
+#define __cpp_lib_invoke_r 202106L
#define __cpp_lib_is_scoped_enum 202011L
#define __cpp_lib_string_contains 202011L
#define __cpp_lib_to_underlying 202102L
diff --git a/libstdc++-v3/testsuite/20_util/function_objects/invoke/4.cc b/libstdc++-v3/testsuite/20_util/function_objects/invoke/4.cc
new file mode 100644
index 00000000000..3ee6711f687
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/function_objects/invoke/4.cc
@@ -0,0 +1,59 @@
+// { dg-options "-std=gnu++2b" }
+// { dg-do compile { target c++23 } }
+
+#include <functional>
+
+#ifndef __cpp_lib_invoke_r
+# error Feature-test macro for invoke_r is missing in <functional>
+#elif __cpp_lib_invoke_r < 202106L
+# error Feature-test macro for invoke_r has the wrong value in <functional>
+#endif
+
+constexpr int sq(int i) { return i * i; }
+
+template<typename Val, typename Expected>
+constexpr bool chk(Val&& val, Expected&& exp)
+{
+ return std::is_same_v<Val, Expected> && val == exp;
+}
+
+void
+test01()
+{
+ static_assert( chk( std::invoke(sq, 2), 4 ) );
+ static_assert( chk( std::invoke_r<int>(sq, 3), 9 ) );
+ static_assert( chk( std::invoke_r<char>(sq, 4), '\x10' ) );
+}
+
+struct abstract {
+ virtual ~abstract() = 0;
+ void operator()() noexcept;
+};
+
+static_assert( noexcept(std::invoke(std::declval<abstract>())),
+ "It should be possible to use abstract types with INVOKE" );
+
+static_assert( noexcept(std::invoke_r<void>(std::declval<abstract>())),
+ "It should be possible to use abstract types with INVOKE<R>" );
+
+struct F {
+ void operator()() &;
+ void operator()() && noexcept;
+ int operator()(int);
+ double* operator()(int, int) noexcept;
+};
+struct D { D(void*); };
+
+static_assert( !noexcept(std::invoke(std::declval<F&>())) );
+static_assert( noexcept(std::invoke(std::declval<F>())) );
+static_assert( !noexcept(std::invoke(std::declval<F>(), 1)) );
+static_assert( noexcept(std::invoke(std::declval<F>(), 1, 2)) );
+
+static_assert( !noexcept(std::invoke_r<void>(std::declval<F&>())) );
+static_assert( noexcept(std::invoke_r<void>(std::declval<F>())) );
+static_assert( !noexcept(std::invoke_r<int>(std::declval<F>(), 1)) );
+static_assert( !noexcept(std::invoke_r<void>(std::declval<F>(), 1)) );
+static_assert( !noexcept(std::invoke_r<long>(std::declval<F>(), 1)) );
+static_assert( noexcept(std::invoke_r<void>(std::declval<F>(), 1, 2)) );
+static_assert( noexcept(std::invoke_r<void*>(std::declval<F>(), 1, 2)) );
+static_assert( !noexcept(std::invoke_r<D>(std::declval<F>(), 1, 2)) );
diff --git a/libstdc++-v3/testsuite/20_util/function_objects/invoke/version.cc b/libstdc++-v3/testsuite/20_util/function_objects/invoke/version.cc
index cf1a46a1ada..2dc71aea504 100644
--- a/libstdc++-v3/testsuite/20_util/function_objects/invoke/version.cc
+++ b/libstdc++-v3/testsuite/20_util/function_objects/invoke/version.cc
@@ -7,3 +7,13 @@
#elif __cpp_lib_invoke < 201411L
# error Feature-test macro for invoke has the wrong value in <version>
#endif
+
+#if __cplusplus > 202002L
+#ifndef __cpp_lib_invoke_r
+# error Feature-test macro for invoke_r is missing in <version>
+#elif __cpp_lib_invoke_r < 202106L
+# error Feature-test macro for invoke_r has the wrong value in <version>
+#endif
+#elif defined __cpp_lib_invoke_r
+# error __cpp_lib_invoke_r is defined in <version> before C++23
+#endif
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