The previous patch fixed perfect forwarding for std::bind_front.
This patch fixes the same issue for std::not_fn.
Tested on x86_64-pc-linux-gnu, does this look OK for trunk and
perhaps 13?
PR libstdc++/111327
libstdc++-v3/ChangeLog:
* include/std/functional (_GLIBCXX_NOT_FN_CALL_OP): Also define
a deleted fallback operator() overload. Constrain both the
main and deleted overloads accordingly.
* testsuite/20_util/function_objects/not_fn/111327.cc: New test.
---
libstdc++-v3/include/std/functional | 10 +++++--
.../20_util/function_objects/not_fn/111327.cc | 29 +++++++++++++++++++
2 files changed, 37 insertions(+), 2 deletions(-)
create mode 100644
libstdc++-v3/testsuite/20_util/function_objects/not_fn/111327.cc
diff --git a/libstdc++-v3/include/std/functional
b/libstdc++-v3/include/std/functional
index c50b9e4d365..9551e38dfdb 100644
--- a/libstdc++-v3/include/std/functional
+++ b/libstdc++-v3/include/std/functional
@@ -1061,7 +1061,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// forwarding _M_fn and the function arguments with the same qualifiers,
// and deducing the return type and exception-specification.
#define _GLIBCXX_NOT_FN_CALL_OP( _QUALS ) \
- template<typename... _Args> \
+ template<typename... _Args, \
+ typename = enable_if_t<__is_invocable<_Fn _QUALS,
_Args...>::value>> \
_GLIBCXX20_CONSTEXPR \
decltype(_S_not<__inv_res_t<_Fn _QUALS, _Args...>>()) \
operator()(_Args&&... __args) _QUALS \
@@ -1070,7 +1071,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{ \
return !std::__invoke(std::forward< _Fn _QUALS >(_M_fn), \
std::forward<_Args>(__args)...); \
- }
+ } \
+ \
+ template<typename... _Args, \
+ typename = enable_if_t<!__is_invocable<_Fn _QUALS,
_Args...>::value>> \
+ void operator()(_Args&&... __args) _QUALS = delete;
+
_GLIBCXX_NOT_FN_CALL_OP( & )
_GLIBCXX_NOT_FN_CALL_OP( const & )
_GLIBCXX_NOT_FN_CALL_OP( && )
diff --git a/libstdc++-v3/testsuite/20_util/function_objects/not_fn/111327.cc
b/libstdc++-v3/testsuite/20_util/function_objects/not_fn/111327.cc
new file mode 100644
index 00000000000..93e00ee8057
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/function_objects/not_fn/111327.cc
@@ -0,0 +1,29 @@
+// PR libstdc++/111327 - std::bind_front (and std::not_fn) doesn't perfectly
+// forward according to value category of the call wrapper object
+// { dg-do compile { target c++17 } }
+
+#include <functional>
+#include <utility>
+
+struct F {
+ void operator()(...) & = delete;
+ bool operator()(...) const &;
+};
+
+struct G {
+ void operator()(...) && = delete;
+ bool operator()(...) const &&;
+};
+
+int main() {
+ auto f = std::not_fn(F{});
+ f(); // { dg-error "deleted" }
+ std::move(f)();
+ std::as_const(f)();
+ std::move(std::as_const(f))();
+
+ auto g = std::not_fn(G{});
+ g(); // { dg-error "deleted" }
+ std::move(g)(); // { dg-error "deleted" }
+ std::move(std::as_const(g))();
+}
--
2.42.0.158.g94e83dcf5b
