From f945509739602000305fa4fe4b35ce26c9474fa2 Mon Sep 17 00:00:00 2001
From: MURAOKA Taro <koron.kaoriya@gmail.com>
Date: Thu, 13 Jul 2023 00:57:00 +0900
Subject: [PATCH] Specialize the conversion between wchar_t* and Go string on
 Windows only.

---
 wchar.go         |  2 ++
 wchar_windows.go | 27 +++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)
 create mode 100644 wchar_windows.go

diff --git a/wchar.go b/wchar.go
index 8ec3566..9c4c870 100644
--- a/wchar.go
+++ b/wchar.go
@@ -21,6 +21,8 @@
 // OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 // SUCH DAMAGE.
 
+//go:build !windows
+
 package hid
 
 /*
diff --git a/wchar_windows.go b/wchar_windows.go
new file mode 100644
index 0000000..701de37
--- /dev/null
+++ b/wchar_windows.go
@@ -0,0 +1,27 @@
+package hid
+
+/*
+#include <wchar.h>
+*/
+import "C"
+
+import (
+	"golang.org/x/sys/windows"
+)
+
+// gotowcs converts a Go string to a C wide string. The returned string must
+// be freed by the caller by calling C.free.
+func gotowcs(s string) *C.wchar_t {
+	u16s, err := windows.UTF16FromString(s)
+	if err != nil {
+		panic(err)
+	}
+	n := C.size_t(len(u16s))
+	wcs := (*C.wchar_t)(calloc(n+1, C.sizeof_wchar_t))
+	return C.wmemcpy(wcs, (*C.wchar_t)(&u16s[0]), n)
+}
+
+// wcstogo converts a C wide string to a Go string.
+func wcstogo(wcs *C.wchar_t) string {
+	return windows.UTF16PtrToString((*uint16)(wcs))
+}