[GNATS 26590] Spurious diagnostic no instance of function template " "boost::asio::any_completion_handler<Signatures...>::operator() [with Signatures=<void ()>]" matches the argument lis

[jhsedg]

Customer bug ID

any_completion_handler.cpp, 26590.C reduced test is 26590a.C

Description

​cpfe -DTEST_NUMBER=1 --gnu_version=120100 -w --no_inlining --no_wrap_diagnostics --display_error --c++20 -tused Test_name.c
​"../libs/asio/test/any_completion_handler.cpp", line 249: error #304: no instance of function template "boost::asio::a
​ny_completion_handler<Signatures...>::operator() [with Signatures=<void ()>]" matches the argument list
​ object type is: boost::asio::any_completion_handler<void ()>
​ std::move(h1)();
​ ^
​"../boost/asio/any_completion_handler.hpp", line 747: note #3327-D: candidate function template "boost::asio::any_comp
​letion_handler<Signatures...>::operator() [with Signatures=<void ()>]" failed deduction
​ auto operator()(Args&&... args)
​ ^
​
​"../libs/asio/test/any_completion_handler.cpp", line 260: error #304: no instance of function template "boost::asio::a
​ny_completion_handler<Signatures...>::operator() [with Signatures=<void (boost::system::error_code)>]" matches the arg
​ument list
​ argument types are: (boost::asio::error::misc_errors)
​ object type is: boost::asio::any_completion_handler<void (boost::system::error_code)>
​ std::move(h2)(boost::asio::error::eof);
​ ^
​"../boost/asio/any_completion_handler.hpp", line 747: note #3327-D: candidate function template "boost::asio::any_comp
​letion_handler<Signatures...>::operator() [with Signatures=<void (boost::system::error_code)>]" failed deduction
​ auto operator()(Args&&... args)
​ ^
​
​2 errors detected in the compilation of "Test_name.c".
​
​
​This is the reduced test:
​//options_all: --gnu_version=120100 -w --no_inlining --no_wrap_diagnostics --displa
​y_error --c++20 -tused
​namespace boost {
​namespace asio {
​struct any_completion_handler_call_fns {
​ void call(int *);
​};
​struct any_completion_handler_fn_table
​ : private any_completion_handler_call_fns {
​ any_completion_handler_call_fns::call;
​};
​template <typename... Signatures> struct any_completion_handler {
​ any_completion_handler_fn_table fn_table_;
​ int impl_;
​ template <typename... Args>
​ auto operator()(Args... args) -> decltype(fn_table_.call(&impl_, args...));
​};
​} // namespace asio
​} // namespace boost
​void any_completion_handler_invocation_test() {
​ boost::asio::any_completion_handler __trans_tmp_1;
​ __trans_tmp_1();
​}
​cpfe -DTEST_NUMBER=1 --gnu_version=120100 -w --no_inlining --no_wrap_diagnostics --
​display_error --c++20 -tused Test_name.c
​"Test_name.c", line 21: error #304: no instance of function template "boost::asio::
​any_completion_handler<Signatures...>::operator() [with Signatures=<>]" matches the
​ argument list
​ object type is: boost::asio::any_completion_handler<>
​ trans_tmp_1();
​ ^
​"Test_name.c", line 15: note #3327-D: candidate function template "boost::asio::any
​_completion_handler<Signatures...>::operator() [with Signatures=<>]" failed deducti
​on
​ auto operator()(Args... args) -> decltype(fn_table.call(&impl, args...));
​ ^
​
​1 error detected in the compilation of "Test_name.c".
​26590a.C:cp::FAIL: