MSVC: unexpected token '__cdecl', expected 'expression' - c++

Question

Porting an application to Windows, I am now trying to compile it with VS2017 and am running into a host of problems. One of which is that a template wrapper I wrote to make a C++ member function available to be called from a C library (FUSE) doesn't work:
template <class T> class Callback {};
template <class T, class ...Arguments>
struct Callback<T(Arguments...)>
{
template <T(operations::*CALLBACK)(Arguments...)>
static T wrap(Arguments... parameters)
{
auto *instance = static_cast<operations*>(fuse_get_context()->private_data);
return (instance->*CALLBACK)(std::forward<Arguments>(parameters)...);
}
};
I am trying to set the callbacks like this in the constructor:
_operations.get_attr = Callback<std::remove_reference<decltype(*_high_level.getattr)>::type>::wrap<&operations::getattr>;
This is - I believe - valid code, but it doesn't comopile with some warnings and an error:
warning C4229: anachronism used: modifiers on data are ignored
error C2760: syntax error: unexpected token '__cdecl', expected 'expression'
note: see reference to function template instantiation 'T Callback<int (const char *,stat64_cygwin *)>::wrap<int operations::getattr(const char *,stat64_cygwin *)>(const char *,stat64_cygwin *)' being compiled
with
[
T=int
]
note: see reference to function template instantiation 'T Callback<int (const char *,stat64_cygwin *)>::wrap<int operations::getattr(const char *,stat64_cygwin *)>(const char *,stat64_cygwin *)' being compiled
with
[
T=int
]
error C2059: syntax error: '__cdecl'
The warning about anachronisms points to the line containing the template specifications for the wrap function. The error points to the line where the callback is actually invoked and returned, inside the wrap function.
It's very confusing, after reading somewhat I found that anachronisms are the sort-of attributes used in Windows APIs, which I don't use here, and I also don't have any __cdecl here. I have no idea how to proceed here.

Answer 1

Renaming CALLBACK to MEMFUNC worked. Apparantly, Windows defines CALLBACK to something unexpected, causing the code to be expanded in a way it doesn't compile.
Besides the fact that it's weird to just define random stuff like this (without prefixing it with WINDOWS_), it's unfortunate that the compiler generates errors which do not properly indicate that it originates in some #define, making it hard to debug.