diff --git a/windows/tools/hresultwrap.cpp b/windows/tools/hresultwrap.cpp
index c6cfc303..ee73ad60 100644
--- a/windows/tools/hresultwrap.cpp
+++ b/windows/tools/hresultwrap.cpp
@@ -28,7 +28,6 @@ bool generate(ByteSlice line, FILE *fout)
 
 	tokens = ByteSliceFields(line);
 
-	new (&item) items;
 	i = 0;
 	item.returns = tokens.at(i);
 	item.keepReturn = false;
@@ -75,8 +74,6 @@ bool generate(ByteSlice line, FILE *fout)
 		genout = genout.AppendString("void");
 	genout = genout.AppendString(")\n");
 
-	item.~items();
-
 	genout = genout.AppendString("\n");
 	nw = fwrite(genout.Data(), sizeof (char), genout.Len(), fout);
 	return nw == genout.Len();
diff --git a/windows/tools/lib.cpp b/windows/tools/lib.cpp
index 310ab7b0..da12dede 100644
--- a/windows/tools/lib.cpp
+++ b/windows/tools/lib.cpp
@@ -267,9 +267,8 @@ void ByteSlice::CopyFrom(const ByteSlice &b)
 Scanner::Scanner(ReadCloser *r)
 {
 	this->r = r;
-	this->buf = new char[nbuf];
-	this->p = this->buf;
-	this->n = 0;
+	this->buf = ByteSlice(nbuf, nbuf);
+	this->p = ByteSlice();
 	this->line = ByteSlice(0, nbuf);
 	this->err = NULL;
 }
@@ -278,7 +277,6 @@ Scanner::~Scanner(void)
 {
 	if (this->err != NULL)
 		delete this->err;
-	delete[] this->buf;
 }
 
 bool Scanner::Scan(void)
@@ -289,23 +287,21 @@ bool Scanner::Scan(void)
 		return false;
 	this->line = this->line.Slice(0, 0);
 	for (;;) {
-		if (this->n > 0) {
+		if (this->p.Len() > 0) {
 			size_t j;
 			bool haveline;
 
 			haveline = false;
-			for (j = 0; j < this->n; j++)
-				if (this->p[j] == '\n') {
+			for (j = 0; j < this->p.Len(); j++)
+				if (this->p.Data()[j] == '\n') {
 					haveline = true;
 					break;
 				}
-			this->line = this->line.Append(this->p, j);
-			this->p += j;
-			this->n -= j;
+			this->line = this->line.Append(this->p.Slice(0, j));
+			this->p = this->p.Slice(j, this->p.Len());
 			if (haveline) {
 				// swallow the \n for the next time through
-				this->p++;
-				this->n--;
+				this->p = this->p.Slice(1, this->p.Len());
 				return true;
 			}
 			// otherwise, the buffer was exhausted in the middle of a line, so fall through
@@ -314,8 +310,7 @@ bool Scanner::Scan(void)
 		this->err = this->r->Read(this->buf, &n);
 		if (this->err != NULL)
 			return false;
-		this->p = this->buf;
-		this->n = n;
+		this->p = this->buf.Slice(0, n);
 	}
 }
 
diff --git a/windows/tools/lib.hpp b/windows/tools/lib.hpp
index 27405481..417d6fbf 100644
--- a/windows/tools/lib.hpp
+++ b/windows/tools/lib.hpp
@@ -24,7 +24,7 @@ public:
 	ByteSlice(ByteSlice &&b);			// move constructor; sets b to ByteSlice()
 	ByteSlice(const char *b, size_t n);
 	ByteSlice(size_t len, size_t cap);
-	ByteSlice(int len, size_t cap);		// deal with stupid rule about 0
+	ByteSlice(int len, size_t cap);		// deal with stupid rule about 0 (see https://stackoverflow.com/a/4610586/3408572)
 	~ByteSlice(void);
 
 	// note: copy assignment does not use copy-and-swap because I get neither copy-and-swap nor ADL public friend swap functions (https://stackoverflow.com/questions/3279543/what-is-the-copy-and-swap-idiom, https://stackoverflow.com/questions/5695548/public-friend-swap-member-function)
@@ -64,9 +64,8 @@ extern Error *CreateWrite(const char *filename, WriteCloser **w);
 
 class Scanner {
 	ReadCloser *r;
-	char *buf;
-	const char *p;
-	size_t n;
+	ByteSlice buf;
+	ByteSlice p;
 	ByteSlice line;
 	Error *err;
 public:
diff --git a/windows/tools/lib_posix.cpp b/windows/tools/lib_posix.cpp
index cd4c9774..1bd855cf 100644
--- a/windows/tools/lib_posix.cpp
+++ b/windows/tools/lib_posix.cpp
@@ -81,7 +81,7 @@ posixWriteCloser::~posixWriteCloser(void)
 	close(this->fd);
 }
 
-Error *posixWriteCloser::Write(const ByteSlice &b)
+Error *posixWriteCloser::Write(const ByteSlice b)
 {
 	ssize_t ret;