Improve wstring_owner, rename to wchar_ptr.

The user-defined conversion function makes the interface a lot simpler
AND safer.

7 files changed, 58 insertions, 57 deletions

diff --git a/c/common.cpp b/c/common.cpp
index 5d786da..59f0fdc 100644
--- a/c/common.cpp
+++ b/c/common.cpp
@@ -3,48 +3,48 @@
 
 #include "common.h"
 
-/* wstring_owner: Simple wrapper for wide C strings. */
+/* wchar_ptr: Simple wrapper for wide C strings. */
 
-wstring_owner::wstring_owner() {}
+wchar_ptr::wchar_ptr() {}
 
-wstring_owner::wstring_owner(wchar_t* const s) : p(s) {}
+wchar_ptr::wchar_ptr(wchar_t* const s) : m_p(s) {}
 
-wstring_owner& wstring_owner::operator=(wchar_t* const s)
+wchar_ptr& wchar_ptr::operator=(wchar_t* const s)
 {
-	if (p != s) {
-		delete p;
-		p = s;
+	if (m_p != s) {
+		delete m_p;
+		m_p = s;
 	}
 	return *this;
 }
 
-wstring_owner::wstring_owner(wstring_owner&& other) noexcept : p(std::exchange(other.p, nullptr)) {}
+wchar_ptr::wchar_ptr(wchar_ptr&& other) noexcept : m_p(std::exchange(other.m_p, nullptr)) {}
 
-wstring_owner& wstring_owner::operator=(wstring_owner&& other) noexcept
+wchar_ptr& wchar_ptr::operator=(wchar_ptr&& other) noexcept
 {
-	std::swap(p, other.p);
+	std::swap(m_p, other.m_p);
 	return *this;
 }
 
-/* Return pointer, releasing ownership. */
-wchar_t* wstring_owner::release()
+wchar_ptr::operator wchar_t*() noexcept
 {
-	wchar_t* p2 = p;
-	p = nullptr;
-	return p2;
+	return m_p;
 }
 
-wstring_owner::operator bool() const
+/* Return pointer, releasing ownership. */
+wchar_t* wchar_ptr::release()
 {
-	return p;
+	wchar_t* p2 = m_p;
+	m_p = nullptr;
+	return p2;
 }
 
-wstring_owner::~wstring_owner()
+wchar_ptr::~wchar_ptr()
 {
-	delete p;
+	delete m_p;
 }
 
-wstring_owner wstring_owner::from_narrow(const char* const src, const int cp)
+wchar_ptr wchar_ptr::from_narrow(const char* const src, const int cp)
 {
 	int cbMultiByte = strlen(src)+1;
 	int cchWideChar = MultiByteToWideChar(cp, 0, src, cbMultiByte, NULL, 0);
@@ -56,7 +56,7 @@ wstring_owner wstring_owner::from_narrow(const char* const src, const int cp)
 	return dst;
 }
 
-wstring_owner wstring_owner::copy(const wchar_t* const src)
+wchar_ptr wchar_ptr::copy(const wchar_t* const src)
 {
 	const int cb = wcslen(src)+1;
 	wchar_t* dst = new wchar_t[cb];
diff --git a/c/common.h b/c/common.h
index 0851bb6..f011565 100644
--- a/c/common.h
+++ b/c/common.h
@@ -8,21 +8,22 @@
 int EBMessageBox(const wchar_t* wszText, const wchar_t* wszCaption, unsigned uType);
 int GetRelativeCursorPos(HWND hWnd, POINT* pt);
 
-struct wstring_owner
+struct wchar_ptr
 {
-	static wstring_owner from_narrow(const char* buf, int cp = CP_UTF8);
-	static wstring_owner copy(const wchar_t* s);
-	wstring_owner();
-	wstring_owner(wchar_t* s);
-	wstring_owner& operator=(wchar_t* s);
-	wstring_owner(wstring_owner& other) = delete;
-	wstring_owner& operator=(wstring_owner& other) = delete;
-	wstring_owner(wstring_owner&& other) noexcept;
-	wstring_owner& operator=(wstring_owner&& other) noexcept;
+	static wchar_ptr from_narrow(const char* buf, int cp = CP_UTF8);
+	static wchar_ptr copy(const wchar_t* s);
+	wchar_ptr();
+	wchar_ptr(wchar_t* s);
+	wchar_ptr& operator=(wchar_t* s);
+	wchar_ptr(wchar_ptr& other) = delete;
+	wchar_ptr& operator=(wchar_ptr& other) = delete;
+	wchar_ptr(wchar_ptr&& other) noexcept;
+	wchar_ptr& operator=(wchar_ptr&& other) noexcept;
+	operator wchar_t*() noexcept;
 	wchar_t *release();
-	operator bool() const;
-	~wstring_owner();
-	wchar_t* p = nullptr;
+	~wchar_ptr();
+private:
+	wchar_t* m_p = nullptr;
 };
 
 struct Win32Error : public std::exception
diff --git a/c/datalistview.cpp b/c/datalistview.cpp
index ecaa76f..cdc6dfb 100644
--- a/c/datalistview.cpp
+++ b/c/datalistview.cpp
@@ -64,20 +64,20 @@ void DataListView::ShowEpisode(const int iEpisode)
 	LVITEM lviValue = {LVIF_TEXT};
 
 	for (int i = 0; q.NextSolution(std::nothrow); i++) {
-		wstring_owner key;
-		wstring_owner value;
+		wchar_ptr key;
+		wchar_ptr value;
 
 		if (!(PlGet(t+1, &key) && PlGet(t+2, &value)))
 			continue;
 
 		lviKey.iItem = i;
 		lviKey.iSubItem = 0;
-		lviKey.pszText = key.p;
+		lviKey.pszText = key;
 		ListView_InsertItem(hWnd, &lviKey);
 
 		lviValue.iItem = i;
 		lviValue.iSubItem = 1;
-		lviValue.pszText = value.p;
+		lviValue.pszText = value;
 		ListView_SetItem(hWnd, &lviValue);
 	}
 
diff --git a/c/episodelistview.cpp b/c/episodelistview.cpp
index 1c5c9ae..313f82f 100644
--- a/c/episodelistview.cpp
+++ b/c/episodelistview.cpp
@@ -264,16 +264,16 @@ int CALLBACK EpisodeListView::SortProc(const LPARAM iItem1, const LPARAM iItem2,
 	case ELVSITITLE:
 	    {
 		Mark m;
-		wstring_owner s1, s2;
+		wchar_ptr s1, s2;
 		int cch, cch1, cch2;
 		if (!Pl("episode_data","episode_title",lvi1.lParam,&s1))
 			return 0;
 		if (!Pl("episode_data","episode_title",lvi2.lParam,&s2))
 			return 0;
-		cch1 = wcslen(s1.p);
-		cch2 = wcslen(s2.p);
+		cch1 = wcslen(s1);
+		cch2 = wcslen(s2);
 		cch = cch1 > cch2? cch2: cch1;
-		return order*_wcsnicmp(s1.p, s2.p, cch);
+		return order*_wcsnicmp(s1, s2, cch);
 	    }
 	default:
 		return 0;
@@ -404,12 +404,12 @@ void EpisodeListView::Update()
 /* Update episode name and rating. */
 void EpisodeListView::UpdateItem(const int iItem, const LPARAM lParam)
 {
-	wstring_owner name;
+	wchar_ptr name;
 	if (!Pl("episode_data","episode_title",lParam,&name)) {
 		if (!Pl("episode_data","update_episode_data")) goto r;
 		if (!Pl("episode_data","episode_title",lParam,&name)) goto r;
 	}
-	ListView_SetItemText(hWnd, iItem, ELVSITITLE, name.p);
+	ListView_SetItemText(hWnd, iItem, ELVSITITLE, name);
 
 r:	int rating;
 	if (!Pl("episode_data","episode_rating",lParam,&rating)) {
diff --git a/c/main.cpp b/c/main.cpp
index 32187c8..3ec6fee 100644
--- a/c/main.cpp
+++ b/c/main.cpp
@@ -56,7 +56,7 @@ static void UpdateTheme();
 void OnTerminate() noexcept
 {
 	const wchar_t* what = L"an exception";
-	wstring_owner why;
+	wchar_ptr why;
 
 	try {
 		std::rethrow_exception(std::current_exception());
@@ -65,14 +65,14 @@ void OnTerminate() noexcept
 		try { why = PlString(t); } catch (...) {}
 	} catch (const Win32Error& e) {
 		what = L"a Windows error";
-		try { why = wstring_owner::copy(e.WhatW()); } catch (...) {}
+		try { why = wchar_ptr::copy(e.WhatW()); } catch (...) {}
 	} catch (const std::exception& e) {
-		try { why = wstring_owner::from_narrow(e.what()); } catch (...) {}
+		try { why = wchar_ptr::from_narrow(e.what()); } catch (...) {}
 	} catch (...) {}
 
 	wchar_t msg[256] = {0};
 	if (why)
-		wszf(msg, L"Episode Browser was terminated due to %s: %s", what, why.p);
+		wszf(msg, L"Episode Browser was terminated due to %s: %s", what, static_cast<wchar_t*>(why));
 	else
 		wszf(msg, L"Episode Browser was terminated due to %s.", what);
 
@@ -493,13 +493,13 @@ void WaitFor(const char* mod, const char* pred)
 	static atom_t aThread;
 	static int bActive;
 	static int iTimer;
-	static wstring_owner activePred;
+	static wchar_ptr activePred;
 
 	if (bActive) {
 		wchar_t msg[256] = {0};
 		wszf(msg, L"Another task (%s) is active. "
 		    L"Do you want to cancel the existing task and start a new one?",
-		    activePred.p);
+		    static_cast<wchar_t*>(activePred));
 		if (EBMessageBox(msg, L"Error", MB_YESNO|MB_ICONWARNING) != IDYES)
 			return;
 		KillTimer(NULL, iTimer);
@@ -529,7 +529,7 @@ void WaitFor(const char* mod, const char* pred)
 	Plx(mod,"thread_create",pred,&aThread);
 	SendMessage(g_hWndStatus, SB_SETTEXT, MAKEWPARAM(1,0), (LPARAM)L".");
 	if (prefer(iTimer = SetTimer(NULL, -1, 500, proc))) {
-		activePred = wstring_owner::from_narrow(pred);
+		activePred = wchar_ptr::from_narrow(pred);
 		bActive = 1;
 	}
 }
diff --git a/c/pl.cpp b/c/pl.cpp
index 1dc22fb..8b3fcbe 100644
--- a/c/pl.cpp
+++ b/c/pl.cpp
@@ -90,11 +90,11 @@ int Query::NextSolution()
 }
 
 /* Convert Prolog term to wide characters. */
-wstring_owner PlString(const term_t t, const int flags)
+wchar_ptr PlString(const term_t t, const int flags)
 {
 	char* s;
 	if (PL_get_chars(t, &s, flags))
-		return {wstring_owner::from_narrow(s)};
+		return {wchar_ptr::from_narrow(s)};
 	else
 		return {};
 }
diff --git a/c/pl.h b/c/pl.h
index 1c526a0..28e13b0 100644
--- a/c/pl.h
+++ b/c/pl.h
@@ -7,7 +7,7 @@
 
 #include "common.h"
 
-wstring_owner PlString(const term_t t, const int flags = CVT_WRITE);
+wchar_ptr PlString(const term_t t, const int flags = CVT_WRITE);
 
 struct Frame
 {
@@ -54,7 +54,7 @@ inline int PlPut(term_t, long*) { return -1; }
 inline int PlPut(term_t, long long*) { return -1; }
 inline int PlPut(term_t, atom_t*) { return -1; }
 inline int PlPut(term_t, char**) { return -1; }
-inline int PlPut(term_t, wstring_owner*) { return -1; }
+inline int PlPut(term_t, wchar_ptr*) { return -1; }
 
 inline int PlGet(term_t, int) { return -1; }
 inline int PlGet(term_t, long) { return -1; }
@@ -67,11 +67,11 @@ inline int PlGet(term_t t, long* x) { return PL_get_long(t, x); }
 inline int PlGet(term_t t, long long* x) { return PL_get_int64(t, x); }
 inline int PlGet(term_t t, atom_t* x) { return PL_get_atom(t, x); }
 inline int PlGet(term_t t, char** x) { return PL_get_atom_chars(t, x); }
-inline int PlGet(term_t t, wstring_owner* x) {
+inline int PlGet(term_t t, wchar_ptr* x) {
 	Mark m;
 	char* s;
 	if (!PlGet(t, &s)) return 0;
-	*x = wstring_owner::from_narrow(s);
+	*x = wchar_ptr::from_narrow(s);
 	return 1; /* or catch potential exception from BstrFromSz? */
 }