AK: Simplify constructors and conversions from nullptr_t

Problem:
- Many constructors are defined as `{}` rather than using the ` =
  default` compiler-provided constructor.
- Some types provide an implicit conversion operator from `nullptr_t`
  instead of requiring the caller to default construct. This violates
  the C++ Core Guidelines suggestion to declare single-argument
  constructors explicit
  (https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#c46-by-default-declare-single-argument-constructors-explicit).

Solution:
- Change default constructors to use the compiler-provided default
  constructor.
- Remove implicit conversion operators from `nullptr_t` and change
  usage to enforce type consistency without conversion.

1 files changed, 1 insertions, 1 deletions

diff --git a/Kernel/Syscalls/socket.cpp b/Kernel/Syscalls/socket.cpp
index 2fdf7f8b3b..0e596707c0 100644
--- a/Kernel/Syscalls/socket.cpp
+++ b/Kernel/Syscalls/socket.cpp
@@ -115,7 +115,7 @@ int Process::sys$accept(int accepting_socket_fd, Userspace<sockaddr*> user_addre
     if (!socket.can_accept()) {
         if (accepting_socket_description->is_blocking()) {
             auto unblock_flags = Thread::FileBlocker::BlockFlags::None;
-            if (Thread::current()->block<Thread::AcceptBlocker>(nullptr, *accepting_socket_description, unblock_flags).was_interrupted())
+            if (Thread::current()->block<Thread::AcceptBlocker>({}, *accepting_socket_description, unblock_flags).was_interrupted())
                 return -EINTR;
         } else {
             return -EAGAIN;