Compiler failures under mingw

[cscd98]

The latest version doesn't compile with the following errors using mingw on linux:

/home/cscd98/Developer/dolphin-fml/Externals/cpp-ipc/cpp-ipc/include/libipc/imp/fmt_cpo.h:46:27: error: no match for call to ‘(const ipc::detail_tag_invoke::tag_invoke_t) (ipc::detail_tag_invoke::fmt_to_t, ipc::fmt_context&, std::ios_base& (&)(std::ios_base&))’
   46 |     return ipc::tag_invoke(fmt_to_t{}, ctx, std::forward<A1>(a1));

/home/cscd98/Developer/dolphin-fml/Externals/cpp-ipc/cpp-ipc/include/libipc/imp/generic.h:55:33: error: no matching function for call to ‘tag_invoke(ipc::detail_tag_invoke::fmt_to_t, ipc::fmt_context&, std::ios_base& (&)(std::ios_base&))’
   55 |           -> decltype(tag_invoke(std::forward<T>(tag), std::forward<A>(args)...)) {

/home/cscd98/Developer/dolphin-fml/Externals/cpp-ipc/cpp-ipc/include/libipc/imp/fmt.h:142:29: error: no matching function for call to ‘to_string(ipc::fmt_context&, std::ios_base& (&)(std::ios_base&))’
  142 |   -> decltype(ipc::to_string(ctx, std::forward<T>(arg))) {

/home/cscd98/Developer/dolphin-fml/Externals/cpp-ipc/cpp-ipc/include/libipc/imp/fmt.h:74:20: note:   conversion of argument 2 would be ill-formed:
/home/cscd98/Developer/dolphin-fml/Externals/cpp-ipc/cpp-ipc/include/libipc/imp/fmt.h:142:29: error: invalid conversion from ‘std::ios_base& (*)(std::ios_base&)’ to ‘char’ [-fpermissive]
  142 |   -> decltype(ipc::to_string(ctx, std::forward<T>(arg))) {
      |               ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
      |                             |
      |                             std::ios_base& (*)(std::ios_base&)

[mutouyun]

I have submitted my modification proposal, see pull/173. Could you please verify if it works properly in your MinGW environment? If it's okay, I will merge my PR, and you can add the !defined(__MINGW32__) modification on top of this.

[cscd98]

Can confirm this does build on mingw thanks! I've also updated my PR

[mutouyun]

Done.