diff --git a/direct/src/distributed/cConnectionRepository.cxx b/direct/src/distributed/cConnectionRepository.cxx
index 67d6ec1658..e247c2bd55 100644
--- a/direct/src/distributed/cConnectionRepository.cxx
+++ b/direct/src/distributed/cConnectionRepository.cxx
@@ -803,8 +803,9 @@ handle_update_field_owner() {
       Py_DECREF(dclass_this);
 
       // check if we should forward this update to the owner view
+      vector_uchar data = _di.get_remaining_bytes();
       DCPacker packer;
-      packer.set_unpack_data(_di.get_remaining_bytes());
+      packer.set_unpack_data((const char *)data.data(), data.size(), false);
       int field_id = packer.raw_unpack_uint16();
       DCField *field = dclass->get_field_by_index(field_id);
       if (field->is_ownrecv()) {
@@ -845,8 +846,9 @@ handle_update_field_owner() {
       Py_DECREF(dclass_this);
 
       // check if we should forward this update to the owner view
+      vector_uchar data = _di.get_remaining_bytes();
       DCPacker packer;
-      packer.set_unpack_data(_di.get_remaining_bytes());
+      packer.set_unpack_data((const char *)data.data(), data.size(), false);
       int field_id = packer.raw_unpack_uint16();
       DCField *field = dclass->get_field_by_index(field_id);
       if (true) {//field->is_broadcast()) {
diff --git a/dtool/src/prc/encryptStreamBuf.cxx b/dtool/src/prc/encryptStreamBuf.cxx
index 21a33f93c0..dc38ac5894 100644
--- a/dtool/src/prc/encryptStreamBuf.cxx
+++ b/dtool/src/prc/encryptStreamBuf.cxx
@@ -146,14 +146,15 @@ open_read(istream *source, bool owns_source, const string &password) {
   int iv_length = EVP_CIPHER_iv_length(cipher);
   _read_block_size = EVP_CIPHER_block_size(cipher);
 
-  string iv = sr.extract_bytes(iv_length);
+  unsigned char *iv = (unsigned char *)alloca(iv_length);
+  iv_length = (int)sr.extract_bytes(iv, iv_length);
 
   _read_ctx = EVP_CIPHER_CTX_new();
   nassertv(_read_ctx != NULL);
 
   // Initialize the context
   int result;
-  result = EVP_DecryptInit(_read_ctx, cipher, NULL, (unsigned char *)iv.data());
+  result = EVP_DecryptInit(_read_ctx, cipher, NULL, (unsigned char *)iv);
   nassertv(result > 0);
 
   result = EVP_CIPHER_CTX_set_key_length(_read_ctx, key_length);
@@ -170,7 +171,7 @@ open_read(istream *source, bool owns_source, const string &password) {
   unsigned char *key = (unsigned char *)alloca(key_length);
   result =
     PKCS5_PBKDF2_HMAC_SHA1((const char *)password.data(), password.length(),
-                           (unsigned char *)iv.data(), iv.length(),
+                           iv, iv_length,
                            count * iteration_count_factor + 1,
                            key_length, key);
   nassertv(result > 0);
diff --git a/dtool/src/prc/streamReader.cxx b/dtool/src/prc/streamReader.cxx
index 17252f5dd2..e9fa173ad1 100644
--- a/dtool/src/prc/streamReader.cxx
+++ b/dtool/src/prc/streamReader.cxx
@@ -117,16 +117,18 @@ extract_bytes(unsigned char *into, size_t size) {
  * Extracts the indicated number of bytes in the stream and returns them as a
  * string.  Returns empty string at end-of-file.
  */
-string StreamReader::
+vector_uchar StreamReader::
 extract_bytes(size_t size) {
+  vector_uchar buffer;
   if (_in->eof() || _in->fail()) {
-    return string();
+    return buffer;
   }
 
-  char *buffer = (char *)alloca(size);
-  _in->read(buffer, size);
+  buffer.resize(size);
+  _in->read((char *)&buffer[0], size);
   size_t read_bytes = _in->gcount();
-  return string(buffer, read_bytes);
+  buffer.resize(read_bytes);
+  return buffer;
 }
 
 /**
diff --git a/dtool/src/prc/streamReader.h b/dtool/src/prc/streamReader.h
index bedaa0eeb5..1643dd4a9c 100644
--- a/dtool/src/prc/streamReader.h
+++ b/dtool/src/prc/streamReader.h
@@ -19,6 +19,7 @@
 #include "numeric_types.h"
 #include "littleEndian.h"
 #include "bigEndian.h"
+#include "vector_uchar.h"
 
 /**
  * A class to read sequential binary data directly from an istream.  Its
@@ -71,7 +72,7 @@ PUBLISHED:
   EXTENSION(BLOCKING PyObject *readlines());
 
 public:
-  BLOCKING string extract_bytes(size_t size);
+  BLOCKING vector_uchar extract_bytes(size_t size);
   BLOCKING string readline();
 
 private:
diff --git a/panda/src/downloader/downloadDb.cxx b/panda/src/downloader/downloadDb.cxx
index f2a734af17..a210fba8bd 100644
--- a/panda/src/downloader/downloadDb.cxx
+++ b/panda/src/downloader/downloadDb.cxx
@@ -583,9 +583,7 @@ add_multifile_record(PT(MultifileRecord) mfr) {
  * Verifies magic number, returns the number of multifiles or -1 if invalid
  */
 int DownloadDb::Db::
-parse_header(const string &data) {
-  Datagram dg(data);
-
+parse_header(Datagram dg) {
   // Make sure we have a good header
   DatagramIterator di(dg);
   uint32_t magic_number = di.get_uint32();
@@ -623,8 +621,7 @@ parse_header(const string &data) {
  * record
  */
 int DownloadDb::Db::
-parse_record_header(const string &data) {
-  Datagram dg(data);
+parse_record_header(Datagram dg) {
   DatagramIterator di(dg);
   int32_t record_length = di.get_int32();
   downloader_cat.spam()
@@ -639,14 +636,12 @@ parse_record_header(const string &data) {
  * Parses a multifile record (mfr) and returns one
  */
 PT(DownloadDb::MultifileRecord) DownloadDb::Db::
-parse_mfr(const string &data) {
+parse_mfr(Datagram dg) {
 
   PT(DownloadDb::MultifileRecord) mfr = new DownloadDb::MultifileRecord;
 
-  Datagram dg(data);
   DatagramIterator di(dg);
-  int32_t mfr_name_length = di.get_int32();
-  mfr->_name = di.extract_bytes(mfr_name_length);
+  mfr->_name = di.get_string32();
   mfr->_phase = di.get_float64();
   mfr->_size = di.get_int32();
   mfr->_status = di.get_int32();
@@ -676,14 +671,12 @@ parse_mfr(const string &data) {
  * Parses a file record (fr) and returns one
  */
 PT(DownloadDb::FileRecord) DownloadDb::Db::
-parse_fr(const string &data) {
+parse_fr(Datagram dg) {
 
   PT(DownloadDb::FileRecord) fr = new DownloadDb::FileRecord;
 
-  Datagram dg(data);
   DatagramIterator di(dg);
-  int32_t fr_name_length = di.get_int32();
-  fr->_name = di.extract_bytes(fr_name_length);
+  fr->_name = di.get_string32();
 
   // At one time, we stored files in the database with a backslash separator.
   // Nowadays we use a forward slash, but we should make sure we properly
@@ -706,15 +699,14 @@ parse_fr(const string &data) {
 bool DownloadDb::Db::
 read(StreamReader &sr, bool want_server_info) {
   // Read the header
-  string header;
-  header = sr.extract_bytes(_header_length);
+  vector_uchar header = sr.extract_bytes(_header_length);
   if (header.size() != (size_t)_header_length) {
     downloader_cat.error() << "truncated db file" << endl;
     return false;
   }
 
   // Parse the header
-  int num_multifiles = parse_header(header);
+  int num_multifiles = parse_header(Datagram(move(header)));
   if (num_multifiles < 0) {
     downloader_cat.error() << "invalid db header" << endl;
     return false;
@@ -727,26 +719,26 @@ read(StreamReader &sr, bool want_server_info) {
     // of the record
     int mfr_header_length = sizeof(int32_t);
 
-    string mfr_header = sr.extract_bytes(mfr_header_length);
+    vector_uchar mfr_header = sr.extract_bytes(mfr_header_length);
     if (mfr_header.size() != (size_t)mfr_header_length) {
       downloader_cat.error() << "invalid mfr header" << endl;
       return false;
     }
 
     // Parse the header
-    int mfr_length = parse_record_header(mfr_header);
+    int mfr_length = parse_record_header(Datagram(move(mfr_header)));
 
     // Ok, now that we know the size of the mfr, read it in Make a buffer to
     // read the multifile record into do not count the header length twice
     int read_length = (mfr_length - mfr_header_length);
-    string mfr_record = sr.extract_bytes(read_length);
+    vector_uchar mfr_record = sr.extract_bytes(read_length);
     if (mfr_record.size() != (size_t)read_length) {
       downloader_cat.error() << "invalid mfr record" << endl;
       return false;
     }
 
     // Parse the mfr
-    PT(DownloadDb::MultifileRecord) mfr = parse_mfr(mfr_record);
+    PT(DownloadDb::MultifileRecord) mfr = parse_mfr(Datagram(move(mfr_record)));
 
     // Only read in the individual file info if you are the server
     if (want_server_info) {
@@ -758,27 +750,27 @@ read(StreamReader &sr, bool want_server_info) {
         int fr_header_length = sizeof(int32_t);
 
         // Read the header
-        string fr_header = sr.extract_bytes(fr_header_length);
+        vector_uchar fr_header = sr.extract_bytes(fr_header_length);
         if (fr_header.size() != (size_t)fr_header_length) {
           downloader_cat.error() << "invalid fr header" << endl;
           return false;
         }
 
         // Parse the header
-        int fr_length = parse_record_header(fr_header);
+        int fr_length = parse_record_header(Datagram(move(fr_header)));
 
         // Ok, now that we know the size of the mfr, read it in do not count
         // the header length twice
         int read_length = (fr_length - fr_header_length);
 
-        string fr_record = sr.extract_bytes(read_length);
+        vector_uchar fr_record = sr.extract_bytes(read_length);
         if (fr_record.size() != (size_t)read_length) {
           downloader_cat.error() << "invalid fr record" << endl;
           return false;
         }
 
         // Parse the file record
-        PT(DownloadDb::FileRecord) fr = parse_fr(fr_record);
+        PT(DownloadDb::FileRecord) fr = parse_fr(Datagram(move(fr_record)));
 
         // Add this file record to the current multifilerecord
         mfr->add_file_record(fr);
@@ -900,12 +892,10 @@ write_header(ostream &write_stream) {
   // Write the number of multifiles
   dg.add_int32(get_num_multifiles());
 
-  string msg = dg.get_message();
-
   // Seek back to the beginning of the write stream
   write_stream.seekp(0);
   // Overwrite the old bogus header with the real header
-  write_stream.write(msg.data(), msg.length());
+  write_stream.write((const char *)dg.get_data(), dg.get_length());
   return true;
 }
 
@@ -1100,17 +1090,8 @@ read_version_map(StreamReader &sr) {
 
   for (int i = 0; i < num_entries; i++) {
 
-    // Get the length of the file name
-    int name_length = sr.get_int32();
-    if (sr.get_istream()->fail()) {
-      return false;
-    }
-    downloader_cat.spam()
-      << "DownloadDb::read_version_map() - name length: " << name_length
-      << endl;
-
     // Get the file name
-    string name = sr.extract_bytes(name_length);
+    string name = sr.get_string32();
     downloader_cat.spam()
       << "DownloadDb::read_version_map() - name: " << name << endl;
 
diff --git a/panda/src/downloader/downloadDb.h b/panda/src/downloader/downloadDb.h
index 02adedb3d6..b7f206c3b6 100644
--- a/panda/src/downloader/downloadDb.h
+++ b/panda/src/downloader/downloadDb.h
@@ -171,10 +171,10 @@ public:
     bool multifile_exists(string mfname) const;
     PT(MultifileRecord) get_multifile_record_named(string mfname) const;
     void add_multifile_record(PT(MultifileRecord) mfr);
-    int parse_header(const string &data);
-    int parse_record_header(const string &data);
-    PT(MultifileRecord) parse_mfr(const string &data);
-    PT(FileRecord) parse_fr(const string &data);
+    int parse_header(Datagram dg);
+    int parse_record_header(Datagram dg);
+    PT(MultifileRecord) parse_mfr(Datagram dg);
+    PT(FileRecord) parse_fr(Datagram dg);
     bool read(StreamReader &sr, bool want_server_info);
     bool write(StreamWriter &sw, bool want_server_info);
     Filename _filename;
diff --git a/panda/src/downloader/socketStream.cxx b/panda/src/downloader/socketStream.cxx
index af43847fb5..4e441f8f2b 100644
--- a/panda/src/downloader/socketStream.cxx
+++ b/panda/src/downloader/socketStream.cxx
@@ -50,17 +50,17 @@ SSReader::
 bool SSReader::
 do_receive_datagram(Datagram &dg) {
   if (_tcp_header_size == 0) {
-    _data_expected = _data_so_far.length();
+    _data_expected = _data_so_far.size();
   }
   if (_data_expected == 0) {
     // Read the first two bytes: the datagram length.
-    while ((int)_data_so_far.length() < _tcp_header_size) {
+    while ((int)_data_so_far.size() < _tcp_header_size) {
       int ch = _istream->get();
       if (_istream->eof() || _istream->fail()) {
         _istream->clear();
         return false;
       }
-      _data_so_far += (char)ch;
+      _data_so_far.push_back((unsigned char)ch);
     }
 
     Datagram header(_data_so_far);
@@ -70,7 +70,7 @@ do_receive_datagram(Datagram &dg) {
     } else if (_tcp_header_size == 4) {
       _data_expected = di.get_uint32();
     }
-    _data_so_far = _data_so_far.substr(_tcp_header_size);
+    _data_so_far.erase(_data_so_far.begin(), _data_so_far.begin() + _tcp_header_size);
 
     if (_data_expected == 0) {
       // Empty datagram.
@@ -84,20 +84,19 @@ do_receive_datagram(Datagram &dg) {
   static const size_t buffer_size = 1024;
   char buffer[buffer_size];
 
-  size_t read_count = min(_data_expected - _data_so_far.length(),
-                          buffer_size);
+  size_t read_count = min(_data_expected - _data_so_far.size(), buffer_size);
   _istream->read(buffer, read_count);
   size_t count = _istream->gcount();
   while (count != 0) {
-    _data_so_far.append(buffer, count);
+    _data_so_far.insert(_data_so_far.end(), buffer, buffer + count);
 
-    read_count = min(_data_expected - _data_so_far.length(),
+    read_count = min(_data_expected - _data_so_far.size(),
                      buffer_size);
     _istream->read(buffer, read_count);
     count = _istream->gcount();
   }
 
-  if (_data_so_far.length() < _data_expected) {
+  if (_data_so_far.size() < _data_expected) {
     // Not yet here.  Clear the istream error flag and return false to
     // indicate more coming.
     _istream->clear();
@@ -108,7 +107,7 @@ do_receive_datagram(Datagram &dg) {
   dg.append_data(_data_so_far);
 
   _data_expected = 0;
-  _data_so_far = string();
+  _data_so_far.clear();
 
   return true;
 }
diff --git a/panda/src/downloader/socketStream.h b/panda/src/downloader/socketStream.h
index 36065e42af..84ce907a5e 100644
--- a/panda/src/downloader/socketStream.h
+++ b/panda/src/downloader/socketStream.h
@@ -21,6 +21,7 @@
 #include "pdeque.h"
 #include "typedReferenceCount.h"
 #include "pointerTo.h"
+#include "vector_uchar.h"
 
 // At the present, this module is not compiled if OpenSSL is not available,
 // since the only current use for it is to implement OpenSSL-defined
@@ -54,7 +55,7 @@ private:
 
   istream *_istream;
   size_t _data_expected;
-  string _data_so_far;
+  vector_uchar _data_so_far;
   int _tcp_header_size;
 
 #ifdef SIMULATE_NETWORK_DELAY
diff --git a/panda/src/express/datagram.I b/panda/src/express/datagram.I
index fa6063805b..3bd7812969 100644
--- a/panda/src/express/datagram.I
+++ b/panda/src/express/datagram.I
@@ -42,58 +42,16 @@ Datagram(const void *data, size_t size) :
  * Constructs a datagram from an existing block of data.
  */
 INLINE Datagram::
-Datagram(const string &data) :
+Datagram(vector_uchar data) :
+  _data(move(data)),
 #ifdef STDFLOAT_DOUBLE
   _stdfloat_double(true)
 #else
   _stdfloat_double(false)
 #endif
 {
-  append_data(data);
 }
 
-/**
- *
- */
-INLINE Datagram::
-Datagram(const Datagram &copy) :
-  _data(copy._data),
-  _stdfloat_double(copy._stdfloat_double)
-{
-}
-
-/**
- *
- */
-INLINE void Datagram::
-operator = (const Datagram &copy) {
-  _data = copy._data;
-  _stdfloat_double = copy._stdfloat_double;
-}
-
-#ifdef USE_MOVE_SEMANTICS
-/**
- *
- */
-INLINE Datagram::
-Datagram(Datagram &&from) NOEXCEPT :
-  _data(move(from._data)),
-  _stdfloat_double(from._stdfloat_double)
-{
-}
-#endif  // USE_MOVE_SEMANTICS
-
-#ifdef USE_MOVE_SEMANTICS
-/**
- *
- */
-INLINE void Datagram::
-operator = (Datagram &&from) NOEXCEPT {
-  _data = move(from._data);
-  _stdfloat_double = from._stdfloat_double;
-}
-#endif  // USE_MOVE_SEMANTICS
-
 /**
  * Adds a boolean value to the datagram.
  */
@@ -291,7 +249,7 @@ add_string(const string &str) {
   add_uint16((uint16_t)str.length());
 
   // Add the string
-  append_data(str);
+  append_data(str.data(), str.length());
 }
 
 /**
@@ -304,18 +262,18 @@ add_string32(const string &str) {
   add_uint32((uint32_t)str.length());
 
   // Add the string
-  append_data(str);
+  append_data(str.data(), str.length());
 }
 
 /**
  * Adds a variable-length string to the datagram, as a NULL-terminated string.
  */
 INLINE void Datagram::
-add_z_string(string str) {
+add_z_string(const string &str) {
   // We must not have any nested null characters in the string.
   size_t null_pos = str.find('\0');
   // Add the string (sans the null character).
-  append_data(str.substr(0, null_pos));
+  append_data(str.data(), std::min<size_t>(null_pos, str.length()));
 
   // And the null character.
   add_uint8('\0');
@@ -329,11 +287,11 @@ add_z_string(string str) {
 INLINE void Datagram::
 add_fixed_string(const string &str, size_t size) {
   if (str.length() < size) {
-    append_data(str);
+    append_data(str.data(), str.length());
     pad_bytes(size - str.length());
 
   } else { // str.length() >= size
-    append_data(str.substr(0, size));
+    append_data(str.data(), size);
   }
 }
 
@@ -341,8 +299,8 @@ add_fixed_string(const string &str, size_t size) {
  * Appends some more raw data to the end of the datagram.
  */
 INLINE void Datagram::
-append_data(const string &data) {
-  append_data(data.data(), data.length());
+append_data(const vector_uchar &data) {
+  append_data(data.data(), data.size());
 }
 
 /**
diff --git a/panda/src/express/datagram.h b/panda/src/express/datagram.h
index c2cb3b4c8b..9250ac89d3 100644
--- a/panda/src/express/datagram.h
+++ b/panda/src/express/datagram.h
@@ -39,14 +39,7 @@ class EXPCL_PANDAEXPRESS Datagram : public TypedObject {
 PUBLISHED:
   INLINE Datagram();
   INLINE Datagram(const void *data, size_t size);
-  INLINE Datagram(const string &data);
-  INLINE Datagram(const Datagram &copy);
-  INLINE void operator = (const Datagram &copy);
-
-#ifdef USE_MOVE_SEMANTICS
-  INLINE Datagram(Datagram &&from) NOEXCEPT;
-  INLINE void operator = (Datagram &&from) NOEXCEPT;
-#endif
+  INLINE explicit Datagram(vector_uchar data);
 
   virtual ~Datagram();
 
@@ -80,13 +73,13 @@ PUBLISHED:
 
   INLINE void add_string(const string &str);
   INLINE void add_string32(const string &str);
-  INLINE void add_z_string(string str);
+  INLINE void add_z_string(const string &str);
   INLINE void add_fixed_string(const string &str, size_t size);
   void add_wstring(const wstring &str);
 
   void pad_bytes(size_t size);
   void append_data(const void *data, size_t size);
-  INLINE void append_data(const string &data);
+  INLINE void append_data(const vector_uchar &data);
 
   void assign(const void *data, size_t size);
 
diff --git a/panda/src/express/datagramIterator.I b/panda/src/express/datagramIterator.I
index cefde399f2..42c25eeed4 100644
--- a/panda/src/express/datagramIterator.I
+++ b/panda/src/express/datagramIterator.I
@@ -422,14 +422,13 @@ skip_bytes(size_t size) {
  * Returns the remaining bytes in the datagram as a string, but does not
  * extract them from the iterator.
  */
-INLINE string DatagramIterator::
+INLINE vector_uchar DatagramIterator::
 get_remaining_bytes() const {
-  nassertr(_datagram != (const Datagram *)NULL, "");
-  nassertr(_current_index <= _datagram->get_length(), "");
+  nassertr(_datagram != (const Datagram *)NULL, vector_uchar());
+  nassertr(_current_index <= _datagram->get_length(), vector_uchar());
 
-  const char *ptr = (const char *)_datagram->get_data();
-  size_t remaining_size = _datagram->get_length() - _current_index;
-  return string(ptr + _current_index, remaining_size);
+  const unsigned char *ptr = (const unsigned char *)_datagram->get_data();
+  return vector_uchar(ptr + _current_index, ptr + _datagram->get_length());
 }
 
 /**
diff --git a/panda/src/express/datagramIterator.cxx b/panda/src/express/datagramIterator.cxx
index 22ac9ecb19..880719f32b 100644
--- a/panda/src/express/datagramIterator.cxx
+++ b/panda/src/express/datagramIterator.cxx
@@ -119,18 +119,18 @@ get_wstring() {
  * Extracts the indicated number of bytes in the datagram and returns them as
  * a string.
  */
-string DatagramIterator::
+vector_uchar DatagramIterator::
 extract_bytes(size_t size) {
-  nassertr((int)size >= 0, "");
-  nassertr(_datagram != (const Datagram *)NULL, "");
-  nassertr(_current_index + size <= _datagram->get_length(), "");
+  nassertr((int)size >= 0, vector_uchar());
+  nassertr(_datagram != (const Datagram *)NULL, vector_uchar());
+  nassertr(_current_index + size <= _datagram->get_length(), vector_uchar());
 
-  const char *ptr = (const char *)_datagram->get_data();
-  size_t last_index = _current_index;
+  const unsigned char *ptr = (const unsigned char *)_datagram->get_data();
+  ptr += _current_index;
 
   _current_index += size;
 
-  return string(ptr + last_index, size);
+  return vector_uchar(ptr, ptr + size);
 }
 
 /**
diff --git a/panda/src/express/datagramIterator.h b/panda/src/express/datagramIterator.h
index 7126901324..ec76be3f07 100644
--- a/panda/src/express/datagramIterator.h
+++ b/panda/src/express/datagramIterator.h
@@ -62,10 +62,10 @@ PUBLISHED:
   wstring get_wstring();
 
   INLINE void skip_bytes(size_t size);
-  string extract_bytes(size_t size);
+  vector_uchar extract_bytes(size_t size);
   size_t extract_bytes(unsigned char *into, size_t size);
 
-  INLINE string get_remaining_bytes() const;
+  INLINE vector_uchar get_remaining_bytes() const;
   INLINE size_t get_remaining_size() const;
 
   INLINE const Datagram &get_datagram() const;
diff --git a/panda/src/express/hashVal.cxx b/panda/src/express/hashVal.cxx
index 7d52dc5a5e..aa08714668 100644
--- a/panda/src/express/hashVal.cxx
+++ b/panda/src/express/hashVal.cxx
@@ -143,11 +143,11 @@ set_from_hex(const string &text) {
 /**
  * Returns the HashVal as a 16-byte binary string.
  */
-string HashVal::
+vector_uchar HashVal::
 as_bin() const {
   Datagram dg;
   write_datagram(dg);
-  return dg.get_message();
+  return vector_uchar((unsigned char *)dg.get_data(), (unsigned char *)dg.get_data() + dg.get_length());
 }
 
 /**
@@ -155,7 +155,7 @@ as_bin() const {
  * false otherwise.
  */
 bool HashVal::
-set_from_bin(const string &text) {
+set_from_bin(const vector_uchar &text) {
   nassertr(text.size() == 16, false);
   Datagram dg(text);
   DatagramIterator dgi(dg);
diff --git a/panda/src/express/hashVal.h b/panda/src/express/hashVal.h
index d0652d1e01..a4b3754614 100644
--- a/panda/src/express/hashVal.h
+++ b/panda/src/express/hashVal.h
@@ -55,8 +55,8 @@ PUBLISHED:
   string as_hex() const;
   bool set_from_hex(const string &text);
 
-  string as_bin() const;
-  bool set_from_bin(const string &text);
+  vector_uchar as_bin() const;
+  bool set_from_bin(const vector_uchar &text);
 
   INLINE void write_datagram(Datagram &destination) const;
   INLINE void read_datagram(DatagramIterator &source);
diff --git a/panda/src/express/multifile.cxx b/panda/src/express/multifile.cxx
index 0d98849efe..5a7d86f17b 100644
--- a/panda/src/express/multifile.cxx
+++ b/panda/src/express/multifile.cxx
@@ -2402,7 +2402,7 @@ check_signatures() {
     nassertv(stream != NULL);
     StreamReader reader(*stream);
     size_t sig_size = reader.get_uint32();
-    string sig_string = reader.extract_bytes(sig_size);
+    vector_uchar sig_data = reader.extract_bytes(sig_size);
 
     size_t num_certs = reader.get_uint32();
 
@@ -2470,9 +2470,7 @@ check_signatures() {
 
       // Now check that the signature matches the hash.
       int verify_result =
-        EVP_VerifyFinal(md_ctx,
-                        (unsigned char *)sig_string.data(),
-                        sig_string.size(), pkey);
+        EVP_VerifyFinal(md_ctx, sig_data.data(), sig_data.size(), pkey);
       if (verify_result == 1) {
         // The signature matches; save the certificate and its chain.
         _signatures.push_back(chain);
diff --git a/panda/src/express/pointerToArray.I b/panda/src/express/pointerToArray.I
index c3a10f3737..535de63d01 100644
--- a/panda/src/express/pointerToArray.I
+++ b/panda/src/express/pointerToArray.I
@@ -92,6 +92,19 @@ PointerToArray(PointerToArray<Element> &&from) NOEXCEPT :
 }
 #endif  // USE_MOVE_SEMANTICS
 
+#ifdef USE_MOVE_SEMANTICS
+/**
+ * Initializes the PTA from a vector.
+ */
+template<class Element>
+INLINE PointerToArray<Element>::
+PointerToArray(pvector<Element> &&from, TypeHandle type_handle) :
+  PointerToArrayBase<Element>(new ReferenceCountedVector<Element>(move(from))),
+  _type_handle(type_handle)
+{
+}
+#endif  // USE_MOVE_SEMANTICS
+
 /**
  *
  */
@@ -710,6 +723,19 @@ ConstPointerToArray(ConstPointerToArray<Element> &&from) NOEXCEPT :
 }
 #endif  // USE_MOVE_SEMANTICS
 
+#ifdef USE_MOVE_SEMANTICS
+/**
+ * Initializes the PTA from a vector.
+ */
+template<class Element>
+INLINE ConstPointerToArray<Element>::
+ConstPointerToArray(pvector<Element> &&from, TypeHandle type_handle) :
+  PointerToArrayBase<Element>(new ReferenceCountedVector<Element>(move(from))),
+  _type_handle(type_handle)
+{
+}
+#endif  // USE_MOVE_SEMANTICS
+
 /**
  *
  */
diff --git a/panda/src/express/pointerToArray.h b/panda/src/express/pointerToArray.h
index 762a6cb8ce..4e8a052e0f 100644
--- a/panda/src/express/pointerToArray.h
+++ b/panda/src/express/pointerToArray.h
@@ -141,6 +141,7 @@ public:
 
 #ifdef USE_MOVE_SEMANTICS
   INLINE PointerToArray(PointerToArray<Element> &&from) NOEXCEPT;
+  INLINE explicit PointerToArray(pvector<Element> &&from, TypeHandle type_handle = get_type_handle(Element));
 #endif
 
 public:
@@ -302,6 +303,7 @@ PUBLISHED:
 #ifdef USE_MOVE_SEMANTICS
   INLINE ConstPointerToArray(PointerToArray<Element> &&from) NOEXCEPT;
   INLINE ConstPointerToArray(ConstPointerToArray<Element> &&from) NOEXCEPT;
+  INLINE explicit ConstPointerToArray(pvector<Element> &&from, TypeHandle type_handle = get_type_handle(Element));
 #endif
 
   // Duplicating the interface of vector.
diff --git a/panda/src/express/pointerToArrayBase.I b/panda/src/express/pointerToArrayBase.I
index 89acba1206..de8c17d843 100644
--- a/panda/src/express/pointerToArrayBase.I
+++ b/panda/src/express/pointerToArrayBase.I
@@ -39,6 +39,16 @@ ReferenceCountedVector(const Element *begin, const Element *end, TypeHandle type
 {
 }
 
+/**
+ * Creates an array that takes its elements from the given vector.
+ */
+template<class Element>
+INLINE ReferenceCountedVector<Element>::
+ReferenceCountedVector(pvector<Element> &&from) :
+  pvector<Element>(move(from))
+{
+}
+
 /**
  *
  */
diff --git a/panda/src/express/pointerToArrayBase.h b/panda/src/express/pointerToArrayBase.h
index 3220ca4c70..8c33f69be2 100644
--- a/panda/src/express/pointerToArrayBase.h
+++ b/panda/src/express/pointerToArrayBase.h
@@ -43,6 +43,7 @@ public:
   INLINE ReferenceCountedVector(TypeHandle type_handle);
   INLINE ReferenceCountedVector(size_type initial_size, TypeHandle type_handle);
   INLINE ReferenceCountedVector(const Element *begin, const Element *end, TypeHandle type_handle);
+  INLINE ReferenceCountedVector(pvector<Element> &&from);
   ALLOC_DELETED_CHAIN(ReferenceCountedVector<Element>);
 
   INLINE size_type size() const;
diff --git a/panda/src/gobj/texture.cxx b/panda/src/gobj/texture.cxx
index c4a8149ab4..5328b921d9 100644
--- a/panda/src/gobj/texture.cxx
+++ b/panda/src/gobj/texture.cxx
@@ -4207,7 +4207,9 @@ bool Texture::
 do_read_ktx(CData *cdata, istream &in, const string &filename, bool header_only) {
   StreamReader ktx(in);
 
-  if (ktx.extract_bytes(12) != "\xABKTX 11\xBB\r\n\x1A\n") {
+  unsigned char magic[12];
+  if (ktx.extract_bytes(magic, 12) != 12 ||
+      memcmp(magic, "\xABKTX 11\xBB\r\n\x1A\n", 12) != 0) {
     gobj_cat.error()
       << filename << " is not a KTX file.\n";
     return false;
diff --git a/panda/src/movies/wavAudioCursor.cxx b/panda/src/movies/wavAudioCursor.cxx
index 3b220749c4..ccfaa9733e 100644
--- a/panda/src/movies/wavAudioCursor.cxx
+++ b/panda/src/movies/wavAudioCursor.cxx
@@ -106,7 +106,8 @@ WavAudioCursor(WavAudio *src, istream *stream) :
   nassertv(stream != NULL);
 
   // Beginning of "RIFF" chunk.
-  if (_reader.extract_bytes(4) != "RIFF") {
+  unsigned char magic[4];
+  if (_reader.extract_bytes(magic, 4) != 4 || memcmp(magic, "RIFF", 4) != 0) {
     movies_cat.error()
       << ".wav file is not a valid RIFF file.\n";
     return;
@@ -114,7 +115,7 @@ WavAudioCursor(WavAudio *src, istream *stream) :
 
   unsigned int chunk_size = _reader.get_uint32();
 
-  if (_reader.extract_bytes(4) != "WAVE") {
+  if (_reader.extract_bytes(magic, 4) != 4 || memcmp(magic, "WAVE", 4) != 0) {
     movies_cat.error()
       << ".wav file is a RIFF file but does not start with a WAVE chunk.\n";
     return;
@@ -126,10 +127,10 @@ WavAudioCursor(WavAudio *src, istream *stream) :
 
   while ((!have_fmt || !have_data) && _stream->good() && (bytes_read + 8) < chunk_size) {
 
-    string subchunk_id = _reader.extract_bytes(4);
+    _reader.extract_bytes(magic, 4);
     unsigned int subchunk_size = _reader.get_uint32();
 
-    if (subchunk_id == "fmt ") {
+    if (memcmp(magic, "fmt ", 4) == 0) {
       // The format chunk specifies information about the storage.
       nassertv(subchunk_size >= 16);
       have_fmt = true;
@@ -202,7 +203,7 @@ WavAudioCursor(WavAudio *src, istream *stream) :
         _reader.skip_bytes(subchunk_size - read_bytes);
       }
 
-    } else if (subchunk_id == "data") {
+    } else if (memcmp(magic, "data", 4) == 0) {
       // The data chunk contains the actual sammples.
       if (!have_fmt) {
         movies_cat.error()
diff --git a/panda/src/recorder/socketStreamRecorder.cxx b/panda/src/recorder/socketStreamRecorder.cxx
index 1b9493fc03..6209239044 100644
--- a/panda/src/recorder/socketStreamRecorder.cxx
+++ b/panda/src/recorder/socketStreamRecorder.cxx
@@ -82,8 +82,10 @@ play_frame(DatagramIterator &scan, BamReader *manager) {
 
   int num_packets = scan.get_uint16();
   for (int i = 0; i < num_packets; i++) {
-    string packet = scan.get_string();
-    _data.push_back(Datagram(packet));
+    size_t size = scan.get_uint16();
+    vector_uchar packet(size);
+    scan.extract_bytes(&packet[0], size);
+    _data.push_back(Datagram(move(packet)));
   }
 }
 
diff --git a/pandatool/src/flt/fltBeadID.cxx b/pandatool/src/flt/fltBeadID.cxx
index 6346d6282e..f55d3e88cc 100644
--- a/pandatool/src/flt/fltBeadID.cxx
+++ b/pandatool/src/flt/fltBeadID.cxx
@@ -78,9 +78,8 @@ extract_record(FltRecordReader &reader) {
 bool FltBeadID::
 extract_ancillary(FltRecordReader &reader) {
   if (reader.get_opcode() == FO_long_id) {
-    string s = reader.get_iterator().get_remaining_bytes();
-    size_t zero_byte = s.find('\0');
-    _id = s.substr(0, zero_byte);
+    vector_uchar s = reader.get_iterator().get_remaining_bytes();
+    _id.assign((const char *)s.data(), strnlen((const char *)s.data(), s.size()));
     return true;
   }
 
@@ -109,14 +108,11 @@ build_record(FltRecordWriter &writer) const {
 FltError FltBeadID::
 write_ancillary(FltRecordWriter &writer) const {
   if (_id.length() > 7) {
+    Datagram dc;
 
     // Although the manual mentions nothing of this, it is essential that the
     // length of the record be a multiple of 4 bytes.
-    string id = _id;
-    while ((id.length() % 4) != 0) {
-      id += '\0';
-    }
-    Datagram dc(id);
+    dc.add_fixed_string(_id, (_id.length() + 3) & ~3);
 
     FltError result = writer.write_record(FO_long_id, dc);
     if (result != FE_ok) {
diff --git a/pandatool/src/flt/fltRecord.cxx b/pandatool/src/flt/fltRecord.cxx
index c3dc21d070..a0af83e180 100644
--- a/pandatool/src/flt/fltRecord.cxx
+++ b/pandatool/src/flt/fltRecord.cxx
@@ -621,7 +621,8 @@ extract_record(FltRecordReader &) {
 bool FltRecord::
 extract_ancillary(FltRecordReader &reader) {
   if (reader.get_opcode() == FO_comment) {
-    _comment = reader.get_iterator().get_remaining_bytes();
+    vector_uchar s = reader.get_iterator().get_remaining_bytes();
+    _comment.assign((const char *)s.data(), strnlen((const char *)s.data(), s.size()));
     return true;
   }
 
@@ -735,7 +736,7 @@ build_record(FltRecordWriter &) const {
 FltError FltRecord::
 write_ancillary(FltRecordWriter &writer) const {
   if (!_comment.empty()) {
-    Datagram dc(_comment);
+    Datagram dc(_comment.data(), _comment.size());
     FltError result = writer.write_record(FO_comment, dc);
     if (result != FE_ok) {
       return result;