Use windows-rs instead of winapi

Cargo.toml

@@ -16,4 +16,7 @@ categories = ["os", "api-bindings"]
 libc = "^0.2"
 
 [target.'cfg(windows)'.dependencies]
-winapi = { version = "^0.3", features = ["sysinfoapi"] }
+windows = { version = "0.43.0", features = [
+    "Win32_System_SystemInformation",
+    "Win32_Foundation",
+] }

src/lib.rs

@@ -90,36 +90,34 @@ fn gethostname_impl() -> OsString {
 #[inline]
 fn gethostname_impl() -> OsString {
     use std::os::windows::ffi::OsStringExt;
-    use winapi::ctypes::{c_ulong, wchar_t};
-    use winapi::um::sysinfoapi::{ComputerNamePhysicalDnsHostname, GetComputerNameExW};
+    use windows::core::PWSTR;
+    use windows::Win32::System::SystemInformation::{
+        ComputerNamePhysicalDnsHostname, GetComputerNameExW,
+    };
 
-    let mut buffer_size: c_ulong = 0;
+    let mut buffer_size: u32 = 0;
 
     unsafe {
         // This call always fails with ERROR_MORE_DATA, because we pass NULL to
         // get the required buffer size.
         GetComputerNameExW(
             ComputerNamePhysicalDnsHostname,
-            std::ptr::null_mut(),
+            PWSTR::null(),
             &mut buffer_size,
         )
     };
 
-    let mut buffer = vec![0 as wchar_t; buffer_size as usize];
-    let returncode = unsafe {
+    let mut buffer = vec![0 as u16; buffer_size as usize];
+    unsafe {
         GetComputerNameExW(
             ComputerNamePhysicalDnsHostname,
-            buffer.as_mut_ptr() as *mut wchar_t,
+            PWSTR::from_raw(buffer.as_mut_ptr()),
             &mut buffer_size,
         )
-    };
-    // GetComputerNameExW returns a non-zero value on success!
-    if returncode == 0 {
-        panic!(
-            "GetComputerNameExW failed to read hostname: {}
-Please report this issue to <https://github.com/lunaryorn/gethostname.rs/issues>!",
-            Error::last_os_error()
-        );
+        .expect(
+            "GetComputerNameExW failed to read hostname.
+        Please report this issue to <https://github.com/lunaryorn/gethostname.rs/issues>!",
+        )
     }
 
     let end = buffer.iter().position(|&b| b == 0).unwrap_or(buffer.len());