error C2672: 'operator __surrogate_func': no matching overloaded function found

[VzdornovNA88]

example.cpp

(166): error C2672: 'operator __surrogate_func': no matching overloaded function found (199): note: see reference to function template instantiation 'bool print_foo(const T &)' being compiled with [ T=otherlib::one ] (166): error C2893: Failed to specialize function template 'unknown-type bfg::tag::operator ()(Args &&...) noexcept() const' (111): note: see declaration of 'bfg::tag::operator ()' (166): note: With the following template arguments: (166): note: 'Args={const T &}' Compiler returned: 2

I tried to use TAG_INVOKE pattern in my project I was implementing myself variant this pattern but it didn't work then I have found your project and I tried to compile example but I got the same error from msvc.

https://godbolt.org/z/jKjxWq - it is your example in godbolt.org , any msvc compiler compiles its with error "error C2672: 'operator __surrogate_func': no matching overloaded function found" but clang and gcc (c++11->17->20) compile well , What is happening , I don't know , What am I doing wrong? What do you think about it ? Thanks.

[VzdornovNA88]

I solved the problem :
https://developercommunity.visualstudio.com/content/problem/571058/error-c2672-operator-surrogate-func-no-matching-ov.html

on godbolt it works only with msvc v19.28 and compiler option = /std:c++latest

[grafikrobot]

It looks like a bug, as the intent is to have this work on at least vs2017 without the /std:c++latest option. I'll investigate. Thanks for the report.

[VzdornovNA88]

Like I understood it just Msvc can't deduce the return value type in this case however in simple case such as auto f() - >decltype (h()) { return h() ;} then he can and another example if I set concrete return type for tag invoke instead of deduction type it works then. Sorry for my English.