Add AF_UNIX support on windows

Signed-off-by: Piotr Stankiewicz <[email protected]>

Author: Piotr Stankiewicz

httplib.h

@@ -187,6 +187,7 @@ using ssize_t = long;
 #include <io.h>
 #include <winsock2.h>
 #include <ws2tcpip.h>
+#include <afunix.h>
 
 #ifndef WSA_FLAG_NO_HANDLE_INHERIT
 #define WSA_FLAG_NO_HANDLE_INHERIT 0x80
@@ -3538,7 +3539,6 @@ socket_t create_socket(const std::string &host, const std::string &ip, int port,
     hints.ai_flags = socket_flags;
   }
 
-#ifndef _WIN32
   if (hints.ai_family == AF_UNIX) {
     const auto addrlen = host.length();
     if (addrlen > sizeof(sockaddr_un::sun_path)) { return INVALID_SOCKET; }
@@ -3562,10 +3562,18 @@ socket_t create_socket(const std::string &host, const std::string &ip, int port,
           sizeof(addr) - sizeof(addr.sun_path) + addrlen);
 
 #ifndef SOCK_CLOEXEC
+#ifndef _WIN32
       fcntl(sock, F_SETFD, FD_CLOEXEC);
+#endif
 #endif
 
-      if (socket_options) { socket_options(sock); }
+      if (socket_options
+#ifdef _WIN32
+          // Setting SO_REUSEADDR seems not to work well with AF_UNIX on windows, so avoid
+          // setting default_socket_options.
+          && *socket_options.target<void(*)(socket_t)>() != default_socket_options
+#endif
+         ) { socket_options(sock); }
 
       bool dummy;
       if (!bind_or_connect(sock, hints, dummy)) {
@@ -3575,7 +3583,6 @@ socket_t create_socket(const std::string &host, const std::string &ip, int port,
     }
     return sock;
   }
-#endif
 
   auto service = std::to_string(port);