Small improvments.

5 files changed, 50 insertions, 39 deletions

diff --git a/c/CMakeLists.txt b/c/CMakeLists.txt
index b3a1671..da411b2 100644
--- a/c/CMakeLists.txt
+++ b/c/CMakeLists.txt
@@ -35,7 +35,8 @@ target_sources(EpisodeBrowser PRIVATE
   test.h
   util.h
   win.cpp
-  win.h)
+  win.h
+)
 
 if (CMAKE_GENERATOR MATCHES "Visual Studio")
   set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /MANIFEST:NO")
diff --git a/c/data.cpp b/c/data.cpp
index 4db294c..8c26138 100644
--- a/c/data.cpp
+++ b/c/data.cpp
@@ -24,15 +24,15 @@ struct ParsedDoc
 
 	ParsedDoc(const wchar_t* wszUrl, const char* szUrl)
 	{
-		if (!s_hi.Not(0))
+		if (!s_hi.Bad(0))
 			throw Win32Error();
 
 		hiUrl = InternetOpenUrlW(s_hi.v, wszUrl, nullptr, 0, INTERNET_FLAG_NO_UI, 0);
-		if (!hiUrl.Not(0))
+		if (!hiUrl.Bad(0))
 			throw InternetError();
 
 		ctxt = htmlCreatePushParserCtxt(nullptr, nullptr, bufX, sizeof(bufX), szUrl, XML_CHAR_ENCODING_UTF8);
-		if (!ctxt.Not(0))
+		if (!ctxt.Bad(0))
 			throw XmlError();
 
 		htmlCtxtUseOptions(ctxt.v, HTML_PARSE_RECOVER|HTML_PARSE_NOERROR|HTML_PARSE_NOWARNING);
@@ -57,7 +57,7 @@ template <size_t N>
 bool WcharsFromXmlchars(wchar_t (&dst)[N], xmlChar* utf8_)
 {
 	Unique<xmlChar*, XmlFree> utf8 = utf8_;
-	if (!utf8.Not(0))
+	if (!utf8.Bad(0))
 		throw XmlError();
 
 	/* Truncate if source is larger than destination. */
@@ -171,13 +171,13 @@ void FetchData(unsigned char* sig)
 	    "https://www.detectiveconanworld.com/wiki/Anime");
 
 	Unique<xmlXPathContextPtr, xmlXPathFreeContext> xpathCtx = xmlXPathNewContext(doc);
-	if (!xpathCtx.Not(0))
+	if (!xpathCtx.Bad(0))
 		throw XmlError();
 
 	Unique<xmlXPathObjectPtr, xmlXPathFreeObject> xpathObj = xmlXPathEvalExpression(
 	    reinterpret_cast<const xmlChar*>("//tr[./td[1] != '' and ./td[3][@style='background:#f2fde9;']]"),
 	    xpathCtx.v);
-	if (!xpathObj.Not(0))
+	if (!xpathObj.Bad(0))
 		throw XmlError();
 
 	xmlNodeSetPtr nodes = xpathObj.v->nodesetval;
@@ -271,14 +271,14 @@ void FetchScreenwriters(unsigned char* sig)
 		/* Retrieve screenwriter from HTML. */
 		ParsedDoc doc(url, nullptr);
 		Unique<xmlXPathContextPtr, xmlXPathFreeContext> xpathCtx = xmlXPathNewContext(doc);
-		if (!xpathCtx.Not(0))
+		if (!xpathCtx.Bad(0))
 			throw XmlError();
 
 		Unique<xmlXPathObjectPtr, xmlXPathFreeObject> xpathObj =
 			xmlXPathEvalExpression(reinterpret_cast<const xmlChar*>(
 			    "//th[contains(text(), 'Screenplay:')]/following-sibling::td"),
 			    xpathCtx.v);
-		if (!xpathObj.Not(0))
+		if (!xpathObj.Bad(0))
 			throw XmlError();
 
 		xmlNodeSetPtr nodes = xpathObj.v->nodesetval;
diff --git a/c/data.h b/c/data.h
index 478182d..171edaa 100644
--- a/c/data.h
+++ b/c/data.h
@@ -120,11 +120,11 @@ struct FileView
 	{
 		hf = CreateFile(filename, GENERIC_READ|GENERIC_WRITE,
 		    0, nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
-		if (!hf.Not(INVALID_HANDLE_VALUE)) {
+		if (!hf.Bad(INVALID_HANDLE_VALUE)) {
 			if (GetLastError() == ERROR_FILE_NOT_FOUND) {
 				hf = CreateFile(filename, GENERIC_READ|GENERIC_WRITE,
 				    0, nullptr, CREATE_NEW, FILE_ATTRIBUTE_NORMAL, nullptr);
-				if (!hf.Not(INVALID_HANDLE_VALUE))
+				if (!hf.Bad(INVALID_HANDLE_VALUE))
 					throw Win32Error();
 			} else
 				throw Win32Error();
@@ -134,11 +134,11 @@ struct FileView
 		cbMap.QuadPart = c*sizeof(T);
 		hm = CreateFileMapping(hf.v, nullptr, PAGE_READWRITE,
 		    cbMap.HighPart, cbMap.LowPart, nullptr);
-		if (!hm.Not(0))
+		if (!hm.Bad(0))
 			throw Win32Error();
 
 		view = reinterpret_cast<T*>(MapViewOfFile(hm.v, FILE_MAP_ALL_ACCESS, 0, 0, 0));
-		if (!view.Not(0))
+		if (!view.Bad(0))
 			throw Win32Error();
 	}
 
diff --git a/c/ext.cpp b/c/ext.cpp
index 398804e..8e58ade 100644
--- a/c/ext.cpp
+++ b/c/ext.cpp
@@ -87,7 +87,7 @@ static bool FindMatchingFile(wchar_t (&file)[MAX_PATH], const wchar_t* const roo
 
 	WIN32_FIND_DATA fdata;
 	Unique<HANDLE, FindClose> h = FindFirstFileW(pat, &fdata);
-	if (!h.Not(INVALID_HANDLE_VALUE))
+	if (!h.Bad(INVALID_HANDLE_VALUE))
 		throw Win32Error();
 
 	do
diff --git a/c/util.h b/c/util.h
index ffc6b57..f9e3057 100644
--- a/c/util.h
+++ b/c/util.h
@@ -19,42 +19,49 @@
 		_Exit(1);						\
 	})
 
+/* Scope guard. */
 template <typename F>
 struct Finally
 {
 	F f;
-	inline Finally(F f) : f(f) {}
+	inline Finally(F f) noexcept : f(f) {}
 	inline ~Finally() { f(); }
 };
 #define FINALLY Finally _ = [=]()
 
 template <typename T>
-inline void Delete(T v)
+inline void Delete(T v) noexcept
 {
     delete v;
 }
 
+/* Unique is similar to unique_ptr, but it is designed for pointers
+ * and handles of type T, where T is not an RAII class. Further, the
+ * managed object is assumed to be in an invalid state until checked
+ * with Good or Bad. Upon destruction, the object, if valid, is passed
+ * to a given destructor function F. */
 template <typename T, auto F = Delete<T>>
 struct Unique
 {
-	T v;
-	bool ok = true;
-	Unique() : ok(false) {}
-	Unique(T v) : v(v) {}
-	Unique& operator =(T v_)
+	union { T v; };
+	bool ok = false;
+	Unique() noexcept {}
+	Unique(T v) noexcept : v(v) {}
+	Unique& operator =(T v_) noexcept
 	{
-		if (ok)
+		if (ok) {
 			F(v);
+			v.~T();
+		}
 		v = v_;
-		ok = true;
+		ok = false;
 		return *this;
 	}
-	Unique(Unique&& other)
+	Unique(Unique&& other) noexcept : v(std::move(other.v)), ok(other.ok)
 	{
-		v = std::move(other.v);
 		other.ok = false;
 	}
-	Unique& operator =(Unique&& other)
+	Unique& operator =(Unique&& other) noexcept
 	{
 		if (ok)
 			F(v);
@@ -63,17 +70,20 @@ struct Unique
 		other.ok = false;
 		return *this;
 	}
-	bool Not(T u)
+	bool Good(T u) noexcept
 	{
-		if (v == u)
-			return ok = false;
-		else
-			return true;
+		return ok = v == u;
+	}
+	bool Bad(T u) noexcept
+	{
+		return ok = v != u;
 	}
 	~Unique()
 	{
-		if (ok)
+		if (ok) {
 			F(v);
+			v.~T();
+		}
 	}
 };
 
@@ -83,13 +93,13 @@ struct Buf
 {
 	T* data;
 	size_t c;
-	Buf(T* data, size_t c) : data(data), c(c) {}
-	Buf(std::basic_string<T>& s) : data(s.data()), c(s.capacity()) {}
-	template <size_t N> Buf(T (&data)[N]) : data(data), c(N) {}
-	operator T*() { return data; }
-	T& operator *() { return *data; }
-	T& operator [](size_t i) { return data[i]; }
-	Buf<T> operator +(size_t i) { return {data+i, c-i}; }
+	Buf(T* data, size_t c) noexcept : data(data), c(c) {}
+	Buf(std::basic_string<T>& s) noexcept : data(s.data()), c(s.capacity()) {}
+	template <size_t N> Buf(T (&data)[N]) noexcept : data(data), c(N) {}
+	operator T*() noexcept { return data; }
+	T& operator *() noexcept { return *data; }
+	T& operator [](size_t i) noexcept { return data[i]; }
+	Buf<T> operator +(size_t i) noexcept { return {data+i, c-i}; }
 	//T operator -(size_t i) { return {data-i, c+i}; }
 };