diff --git a/include/bit7z/bitarchiveeditor.hpp b/include/bit7z/bitarchiveeditor.hpp
index 6a880434..62e23f42 100644
--- a/include/bit7z/bitarchiveeditor.hpp
+++ b/include/bit7z/bitarchiveeditor.hpp
@@ -23,7 +23,6 @@
 
 #include <istream>
 #include <unordered_map>
-#include <vector>
 
 namespace bit7z {
 
@@ -102,7 +101,7 @@ class BIT7Z_MAYBE_UNUSED BitArchiveEditor final : public BitArchiveWriter {
          * @param index     the index of the item to be updated.
          * @param inBuffer  the buffer containing the new data for the item.
          */
-        void updateItem( uint32_t index, const std::vector< byte_t >& inBuffer );
+        void updateItem( uint32_t index, const buffer_t& inBuffer );
 
         /**
          * @brief Requests to update the content of the item at the specified index
@@ -129,7 +128,7 @@ class BIT7Z_MAYBE_UNUSED BitArchiveEditor final : public BitArchiveWriter {
          * @param itemPath  the path (in the archive) of the item to be updated.
          * @param inBuffer  the buffer containing the new data for the item.
          */
-        void updateItem( const tstring& itemPath, const std::vector< byte_t >& inBuffer );
+        void updateItem( const tstring& itemPath, const buffer_t& inBuffer );
 
         /**
          * @brief Requests to update the content of the item at the specified path
diff --git a/include/bit7z/bitarchivereader.hpp b/include/bit7z/bitarchivereader.hpp
index 137f2bb8..9e8d1394 100644
--- a/include/bit7z/bitarchivereader.hpp
+++ b/include/bit7z/bitarchivereader.hpp
@@ -23,7 +23,6 @@
 #include <istream>
 #include <map>
 #include <system_error>
-#include <vector>
 
 struct IInArchive;
 struct IOutArchive;
@@ -68,7 +67,7 @@ class BitArchiveReader final : public BitAbstractArchiveOpener, public BitInputA
          * @param password      the password needed for opening the input archive.
          */
         BitArchiveReader( const Bit7zLibrary& lib,
-                          const std::vector< byte_t >& inArchive,
+                          const buffer_t& inArchive,
                           const BitInFormat& format BIT7Z_DEFAULT_FORMAT,
                           const tstring& password = {} );
 
diff --git a/include/bit7z/bitarchivewriter.hpp b/include/bit7z/bitarchivewriter.hpp
index 6aeccf08..712dba7f 100644
--- a/include/bit7z/bitarchivewriter.hpp
+++ b/include/bit7z/bitarchivewriter.hpp
@@ -17,7 +17,6 @@
 #include "bittypes.hpp"
 
 #include <istream>
-#include <vector>
 
 namespace bit7z {
 
@@ -56,7 +55,7 @@ class BitArchiveWriter : public BitAbstractArchiveCreator, public BitOutputArchi
          * @param password      (optional) the password needed to read the input archive.
          */
         BitArchiveWriter( const Bit7zLibrary& lib,
-                          const std::vector< byte_t >& inArchive,
+                          const buffer_t& inArchive,
                           const BitInOutFormat& format,
                           const tstring& password = {} );
 
diff --git a/include/bit7z/bitcompressor.hpp b/include/bit7z/bitcompressor.hpp
index 2ec42730..3b8595bc 100644
--- a/include/bit7z/bitcompressor.hpp
+++ b/include/bit7z/bitcompressor.hpp
@@ -21,7 +21,6 @@
 
 #include <ostream>
 #include <type_traits>
-#include <vector>
 
 namespace bit7z {
 
@@ -90,7 +89,7 @@ class BitCompressor : public BitAbstractArchiveCreator {
          * @param inputName  (optional) the name to give to the compressed file inside the output archive.
          */
         void compressFile( Input inFile,
-                           std::vector< byte_t >& outBuffer,
+                           buffer_t& outBuffer,
                            const tstring& inputName = {} ) const {
             BitOutputArchive outputArchive{ *this, outBuffer };
             outputArchive.addFile( inFile, inputName );
diff --git a/include/bit7z/bitextractor.hpp b/include/bit7z/bitextractor.hpp
index 5d5b462b..d7c5277f 100644
--- a/include/bit7z/bitextractor.hpp
+++ b/include/bit7z/bitextractor.hpp
@@ -22,7 +22,6 @@
 #include <algorithm>
 #include <functional>
 #include <map>
-#include <vector>
 #include <ostream>
 
 #ifdef BIT7Z_REGEX_MATCHING
@@ -81,7 +80,7 @@ class BitExtractor final : public BitAbstractArchiveOpener {
          * @param outBuffer   the output buffer where the content of the extracted file will be put.
          * @param index        the index of the file to be extracted from the archive.
          */
-        void extract( Input inArchive, std::vector< byte_t >& outBuffer, uint32_t index = 0 ) const {
+        void extract( Input inArchive, buffer_t& outBuffer, uint32_t index = 0 ) const {
             BitInputArchive inputArchive( *this, inArchive );
             inputArchive.extractTo( outBuffer, index );
         }
@@ -105,7 +104,7 @@ class BitExtractor final : public BitAbstractArchiveOpener {
          * @param inArchive    the input archive to be extracted.
          * @param outMap       the output map.
          */
-        void extract( Input inArchive, std::map< tstring, std::vector< byte_t > >& outMap ) const {
+        void extract( Input inArchive, std::map< tstring, buffer_t >& outMap ) const {
             BitInputArchive inputArchive( *this, inArchive );
             inputArchive.extractTo( outMap );
         }
@@ -141,7 +140,7 @@ class BitExtractor final : public BitAbstractArchiveOpener {
          */
         void extractMatching( Input inArchive,
                               const tstring& itemFilter,
-                              std::vector< byte_t >& outBuffer,
+                              buffer_t& outBuffer,
                               FilterPolicy policy = FilterPolicy::Include ) const {
             if ( itemFilter.empty() ) {
                 throw BitException( "Cannot extract items", make_error_code( BitError::FilterNotSpecified ) );
@@ -221,7 +220,7 @@ class BitExtractor final : public BitAbstractArchiveOpener {
          */
         void extractMatchingRegex( Input inArchive,
                                    const tstring& regex,
-                                   std::vector< byte_t >& outBuffer,
+                                   buffer_t& outBuffer,
                                    FilterPolicy policy = FilterPolicy::Include ) const {
             if ( regex.empty() ) {
                 throw BitException( "Cannot extract items", make_error_code( BitError::FilterNotSpecified ) );
@@ -278,7 +277,7 @@ class BitExtractor final : public BitAbstractArchiveOpener {
         }
 
         void extractMatchingFilter( Input inArchive,
-                                    std::vector< byte_t >& outBuffer,
+                                    buffer_t& outBuffer,
                                     FilterPolicy policy,
                                     const std::function< bool( const tstring& ) >& filter ) const {
             BitInputArchive inputArchive( *this, inArchive );
diff --git a/include/bit7z/bitinputarchive.hpp b/include/bit7z/bitinputarchive.hpp
index 1d5b87b7..b24821ab 100644
--- a/include/bit7z/bitinputarchive.hpp
+++ b/include/bit7z/bitinputarchive.hpp
@@ -25,7 +25,6 @@
 #include <istream>
 #include <map>
 #include <ostream>
-#include <vector>
 
 struct IInStream;
 struct IInArchive;
@@ -63,7 +62,7 @@ class BitInputArchive {
          *                 be used for reading the input archive
          * @param inBuffer the buffer containing the input archive
          */
-        BitInputArchive( const BitAbstractArchiveHandler& handler, const std::vector< byte_t >& inBuffer );
+        BitInputArchive( const BitAbstractArchiveHandler& handler, const buffer_t& inBuffer );
 
         /**
          * @brief Constructs a BitInputArchive object, opening the archive by reading the given input stream.
@@ -152,7 +151,7 @@ class BitInputArchive {
         void extractTo( const tstring& outDir, const std::vector< uint32_t >& indices = {} ) const;
 
         BIT7Z_DEPRECATED_MSG("Since v4.0; please, use the extractTo method.")
-        inline void extract( std::vector< byte_t >& outBuffer, uint32_t index = 0 ) const {
+        inline void extract( buffer_t& outBuffer, uint32_t index = 0 ) const {
             extractTo( outBuffer, index );
         }
 
@@ -162,7 +161,7 @@ class BitInputArchive {
          * @param outBuffer   the output buffer where the content of the archive will be put.
          * @param index       the index of the file to be extracted.
          */
-        void extractTo( std::vector< byte_t >& outBuffer, uint32_t index = 0 ) const;
+        void extractTo( buffer_t& outBuffer, uint32_t index = 0 ) const;
 
         template< std::size_t N >
         BIT7Z_DEPRECATED_MSG("Since v4.0; please, use the extractTo method.")
@@ -231,7 +230,7 @@ class BitInputArchive {
         void extractTo( std::ostream& outStream, uint32_t index = 0 ) const;
 
         BIT7Z_DEPRECATED_MSG("Since v4.0; please, use the extractTo method.")
-        inline void extract( std::map< tstring, std::vector< byte_t > >& outMap ) const {
+        inline void extract( std::map< tstring, buffer_t >& outMap ) const {
             extractTo( outMap );
         }
 
@@ -241,7 +240,7 @@ class BitInputArchive {
          *
          * @param outMap   the output map.
          */
-        void extractTo( std::map< tstring, std::vector< byte_t > >& outMap ) const;
+        void extractTo( std::map< tstring, buffer_t >& outMap ) const;
 
         /**
          * @brief Tests the archive without extracting its content.
diff --git a/include/bit7z/bititemsvector.hpp b/include/bit7z/bititemsvector.hpp
index cba60d92..b896ccc6 100644
--- a/include/bit7z/bititemsvector.hpp
+++ b/include/bit7z/bititemsvector.hpp
@@ -18,7 +18,6 @@
 #include <istream>
 #include <map>
 #include <memory>
-#include <vector>
 
 namespace bit7z {
 
@@ -113,7 +112,7 @@ class BitItemsVector final {
          * @param inBuffer  the buffer containing the file to be indexed in the vector.
          * @param name      user-defined path to be used inside archives.
          */
-        void indexBuffer( const std::vector< byte_t >& inBuffer, const tstring& name );
+        void indexBuffer( const buffer_t& inBuffer, const tstring& name );
 
         /**
          * @brief Indexes the given standard input stream, using the given name as a path when compressed in archives.
diff --git a/include/bit7z/bitmemcompressor.hpp b/include/bit7z/bitmemcompressor.hpp
index 2b91ad9b..97ac001a 100644
--- a/include/bit7z/bitmemcompressor.hpp
+++ b/include/bit7z/bitmemcompressor.hpp
@@ -14,8 +14,6 @@
 #include "bitdefines.hpp"
 #include "bittypes.hpp"
 
-#include <vector>
-
 namespace bit7z {
 
 /**
@@ -25,7 +23,7 @@ namespace bit7z {
  * It let decide various properties of the produced archive, such as the password
  * protection and the compression level desired.
  */
-using BitMemCompressor BIT7Z_MAYBE_UNUSED = BitCompressor< const std::vector< byte_t >& >;
+using BitMemCompressor BIT7Z_MAYBE_UNUSED = BitCompressor< const buffer_t& >;
 
 } // namespace bit7z
 #endif // BITMEMCOMPRESSOR_HPP
diff --git a/include/bit7z/bitmemextractor.hpp b/include/bit7z/bitmemextractor.hpp
index 97742797..d0afcce9 100644
--- a/include/bit7z/bitmemextractor.hpp
+++ b/include/bit7z/bitmemextractor.hpp
@@ -14,14 +14,12 @@
 #include "bitextractor.hpp"
 #include "bittypes.hpp"
 
-#include <vector>
-
 namespace bit7z {
 
 /**
  * @brief The BitMemExtractor alias allows extracting the content of in-memory archives.
  */
-using BitMemExtractor BIT7Z_MAYBE_UNUSED = BitExtractor< const std::vector< byte_t >& >;
+using BitMemExtractor BIT7Z_MAYBE_UNUSED = BitExtractor< const buffer_t& >;
 
 } // namespace bit7z
 
diff --git a/include/bit7z/bitoutputarchive.hpp b/include/bit7z/bitoutputarchive.hpp
index 6ed7f00c..c2e5b5fc 100644
--- a/include/bit7z/bitoutputarchive.hpp
+++ b/include/bit7z/bitoutputarchive.hpp
@@ -24,7 +24,6 @@
 #include <ostream>
 #include <set>
 #include <utility>
-#include <vector>
 
 //! @cond IGNORE_BLOCK_IN_DOXYGEN
 struct ISequentialInStream;
@@ -95,7 +94,7 @@ class BitOutputArchive {
          *                  be used for creating the new archive and reading the (optional) input archive.
          * @param inBuffer  the buffer containing an input archive file.
          */
-        BitOutputArchive( const BitAbstractArchiveCreator& creator, const std::vector< byte_t >& inBuffer );
+        BitOutputArchive( const BitAbstractArchiveCreator& creator, const buffer_t& inBuffer );
 
         /**
          * @brief Constructs a BitOutputArchive object, reading an input file archive from the given std::istream.
@@ -146,7 +145,7 @@ class BitOutputArchive {
          * @param inBuffer  the buffer containing the file to be added to the output archive.
          * @param name      user-defined path to be used inside the output archive.
          */
-        void addFile( const std::vector< byte_t >& inBuffer, const tstring& name );
+        void addFile( const buffer_t& inBuffer, const tstring& name );
 
         /**
          * @brief Adds the given standard input stream, using the given name as a path when compressed
@@ -214,7 +213,7 @@ class BitOutputArchive {
          *
          * @param outBuffer the output buffer.
          */
-        void compressTo( std::vector< byte_t >& outBuffer );
+        void compressTo( buffer_t& outBuffer );
 
         /**
          * @brief Compresses all the items added to this object to the specified buffer.
diff --git a/src/bitarchiveeditor.cpp b/src/bitarchiveeditor.cpp
index b87ce893..9fcd2ad0 100644
--- a/src/bitarchiveeditor.cpp
+++ b/src/bitarchiveeditor.cpp
@@ -36,7 +36,6 @@
 #include <memory>
 #include <string>
 #include <system_error>
-#include <vector>
 
 namespace bit7z {
 
@@ -81,7 +80,7 @@ void BitArchiveEditor::updateItem( uint32_t index, const tstring& inFile ) {
     mEditedItems[ index ] = std::make_unique< FilesystemItem >( tstring_to_path( inFile ), itemName.getNativeString() ); //-V108
 }
 
-void BitArchiveEditor::updateItem( uint32_t index, const std::vector< byte_t >& inBuffer ) {
+void BitArchiveEditor::updateItem( uint32_t index, const buffer_t& inBuffer ) {
     checkIndex( index );
     auto itemName = inputArchive()->itemProperty( index, BitProperty::Path );
     mEditedItems[ index ] = std::make_unique< BufferItem >( inBuffer, itemName.getNativeString() ); //-V108
@@ -98,7 +97,7 @@ void BitArchiveEditor::updateItem( const tstring& itemPath, const tstring& inFil
                                                                                tstring_to_path( itemPath ) );
 }
 
-void BitArchiveEditor::updateItem( const tstring& itemPath, const std::vector< byte_t >& inBuffer ) {
+void BitArchiveEditor::updateItem( const tstring& itemPath, const buffer_t& inBuffer ) {
     mEditedItems[ findItem( itemPath ) ] = std::make_unique< BufferItem >( inBuffer, itemPath ); //-V108
 }
 
diff --git a/src/bitarchivereader.cpp b/src/bitarchivereader.cpp
index 7e646b69..e04431a4 100644
--- a/src/bitarchivereader.cpp
+++ b/src/bitarchivereader.cpp
@@ -27,7 +27,6 @@
 #include <map>
 #include <numeric>
 #include <system_error>
-#include <vector>
 
 namespace bit7z {
 
@@ -38,7 +37,7 @@ BitArchiveReader::BitArchiveReader( const Bit7zLibrary& lib,
     : BitAbstractArchiveOpener( lib, format, password ), BitInputArchive( *this, inArchive ) {}
 
 BitArchiveReader::BitArchiveReader( const Bit7zLibrary& lib,
-                                    const std::vector< byte_t >& inArchive,
+                                    const buffer_t& inArchive,
                                     const BitInFormat& format,
                                     const tstring& password )
     : BitAbstractArchiveOpener( lib, format, password ), BitInputArchive( *this, inArchive ) {}
diff --git a/src/bitarchivewriter.cpp b/src/bitarchivewriter.cpp
index 39dbc953..322dada2 100644
--- a/src/bitarchivewriter.cpp
+++ b/src/bitarchivewriter.cpp
@@ -19,7 +19,6 @@
 #include "bittypes.hpp"
 
 #include <istream>
-#include <vector>
 
 namespace bit7z {
 
@@ -34,7 +33,7 @@ BitArchiveWriter::BitArchiveWriter( const Bit7zLibrary& lib,
       BitOutputArchive( *this, inArchive ) {}
 
 BitArchiveWriter::BitArchiveWriter( const Bit7zLibrary& lib,
-                                    const std::vector< byte_t >& inArchive,
+                                    const buffer_t& inArchive,
                                     const BitInOutFormat& format,
                                     const tstring& password )
     : BitAbstractArchiveCreator( lib, format, password, UpdateMode::Append ),
diff --git a/src/bitinputarchive.cpp b/src/bitinputarchive.cpp
index 51e1323f..94be5418 100644
--- a/src/bitinputarchive.cpp
+++ b/src/bitinputarchive.cpp
@@ -132,7 +132,7 @@ BitInputArchive::BitInputArchive( const BitAbstractArchiveHandler& handler, cons
     mInArchive = openArchiveStream( arcPath, fileStream );
 }
 
-BitInputArchive::BitInputArchive( const BitAbstractArchiveHandler& handler, const std::vector< byte_t >& inBuffer )
+BitInputArchive::BitInputArchive( const BitAbstractArchiveHandler& handler, const buffer_t& inBuffer )
     : mDetectedFormat{ &handler.format() }, // if auto, detect the format from content, otherwise try the passed format.
       mArchiveHandler{ handler } {
     auto bufStream = bit7z::make_com< CBufferInStream, IInStream >( inBuffer );
@@ -215,7 +215,7 @@ void BitInputArchive::extractTo( const tstring& outDir, const std::vector< uint3
     extract_arc( mInArchive, indices, callback );
 }
 
-void BitInputArchive::extractTo( std::vector< byte_t >& outBuffer, uint32_t index ) const {
+void BitInputArchive::extractTo( buffer_t& outBuffer, uint32_t index ) const {
     const uint32_t numberItems = itemsCount();
     if ( index >= numberItems ) {
         throw BitException( "Cannot extract item at the index " + std::to_string( index ),
@@ -228,7 +228,7 @@ void BitInputArchive::extractTo( std::vector< byte_t >& outBuffer, uint32_t inde
     }
 
     const std::vector< uint32_t > indices( 1, index );
-    std::map< tstring, std::vector< byte_t > > buffersMap;
+    std::map< tstring, buffer_t > buffersMap;
     auto extractCallback = bit7z::make_com< BufferExtractCallback, ExtractCallback >( *this, buffersMap );
     extract_arc( mInArchive, indices, extractCallback );
     outBuffer = std::move( buffersMap.begin()->second );
@@ -274,7 +274,7 @@ void BitInputArchive::extractTo( byte_t* buffer, std::size_t size, uint32_t inde
     extract_arc( mInArchive, indices, extractCallback );
 }
 
-void BitInputArchive::extractTo( std::map< tstring, std::vector< byte_t > >& outMap ) const {
+void BitInputArchive::extractTo( std::map< tstring, buffer_t >& outMap ) const {
     const uint32_t numberItems = itemsCount();
     std::vector< uint32_t > filesIndices;
     for ( uint32_t i = 0; i < numberItems; ++i ) {
@@ -288,7 +288,7 @@ void BitInputArchive::extractTo( std::map< tstring, std::vector< byte_t > >& out
 }
 
 void BitInputArchive::test() const {
-    std::map< tstring, std::vector< byte_t > > dummyMap; // output map (not used since we are testing).
+    std::map< tstring, buffer_t > dummyMap; // output map (not used since we are testing).
     auto extractCallback = bit7z::make_com< BufferExtractCallback, ExtractCallback >( *this, dummyMap );
     extract_arc( mInArchive, {}, extractCallback, ExtractMode::Test );
 }
@@ -300,7 +300,7 @@ void BitInputArchive::testItem( uint32_t index ) const {
                             make_error_code( BitError::InvalidIndex ) );
     }
 
-    std::map< tstring, std::vector< byte_t > > dummyMap; // output map (not used since we are testing).
+    std::map< tstring, buffer_t > dummyMap; // output map (not used since we are testing).
     auto extractCallback = bit7z::make_com< BufferExtractCallback, ExtractCallback >( *this, dummyMap );
     extract_arc( mInArchive, { index }, extractCallback, ExtractMode::Test );
 }
diff --git a/src/bititemsvector.cpp b/src/bititemsvector.cpp
index 96bfb38f..951b3947 100644
--- a/src/bititemsvector.cpp
+++ b/src/bititemsvector.cpp
@@ -93,7 +93,7 @@ void BitItemsVector::indexFile( const tstring& inFile, const tstring& name, bool
     mItems.emplace_back( std::make_unique< FilesystemItem >( filePath, tstring_to_path( name ), symlinkPolicy ) );
 }
 
-void BitItemsVector::indexBuffer( const std::vector< byte_t >& inBuffer, const tstring& name ) {
+void BitItemsVector::indexBuffer( const buffer_t& inBuffer, const tstring& name ) {
     mItems.emplace_back( std::make_unique< BufferItem >( inBuffer, tstring_to_path( name ) ) );
 }
 
diff --git a/src/bitoutputarchive.cpp b/src/bitoutputarchive.cpp
index 61d797a3..41fb409b 100644
--- a/src/bitoutputarchive.cpp
+++ b/src/bitoutputarchive.cpp
@@ -78,8 +78,7 @@ BitOutputArchive::BitOutputArchive( const BitAbstractArchiveCreator& creator, co
     mInputArchiveItemsCount = mInputArchive->itemsCount();
 }
 
-BitOutputArchive::BitOutputArchive( const BitAbstractArchiveCreator& creator,
-                                    const std::vector< bit7z::byte_t >& inBuffer )
+BitOutputArchive::BitOutputArchive( const BitAbstractArchiveCreator& creator, const buffer_t& inBuffer )
     : mArchiveCreator{ creator }, mInputArchiveItemsCount{ 0 } {
     if ( !inBuffer.empty() ) {
         mInputArchive = std::make_unique< BitInputArchive >( creator, inBuffer );
@@ -114,7 +113,7 @@ void BitOutputArchive::addFile( const tstring& inFile, const tstring& name ) {
                                !mArchiveCreator.storeSymbolicLinks() );
 }
 
-void BitOutputArchive::addFile( const std::vector< byte_t >& inBuffer, const tstring& name ) {
+void BitOutputArchive::addFile( const buffer_t& inBuffer, const tstring& name ) {
     mNewItemsVector.indexBuffer( inBuffer, name );
 }
 
@@ -258,7 +257,7 @@ void BitOutputArchive::compressTo( const tstring& outFile ) {
     compressToFile( outPath, updateCallback );
 }
 
-void BitOutputArchive::compressTo( std::vector< byte_t >& outBuffer ) {
+void BitOutputArchive::compressTo( buffer_t& outBuffer ) {
     if ( !outBuffer.empty() ) {
         const OverwriteMode overwriteMode = mArchiveCreator.overwriteMode();
         if ( overwriteMode == OverwriteMode::Skip ) {
diff --git a/src/internal/bufferextractcallback.cpp b/src/internal/bufferextractcallback.cpp
index 3f011570..a1f74f5b 100644
--- a/src/internal/bufferextractcallback.cpp
+++ b/src/internal/bufferextractcallback.cpp
@@ -25,7 +25,7 @@
 namespace bit7z {
 
 BufferExtractCallback::BufferExtractCallback( const BitInputArchive& inputArchive,
-                                              std::map< tstring, std::vector< byte_t > >& buffersMap )
+                                              std::map< tstring, buffer_t >& buffersMap )
     : ExtractCallback( inputArchive ),
       mBuffersMap( buffersMap ) {}
 
diff --git a/src/internal/bufferextractcallback.hpp b/src/internal/bufferextractcallback.hpp
index 8c2c7f13..58bcc2f0 100644
--- a/src/internal/bufferextractcallback.hpp
+++ b/src/internal/bufferextractcallback.hpp
@@ -10,19 +10,20 @@
 #ifndef BUFFEREXTRACTCALLBACK_HPP
 #define BUFFEREXTRACTCALLBACK_HPP
 
-#include "bitinputarchive.hpp"
 #include "bittypes.hpp"
 #include "internal/extractcallback.hpp"
 
-#include <vector>
+#include <cstdint>
 #include <map>
 
 namespace bit7z {
 
+class BitInputArchive;
+
 class BufferExtractCallback final : public ExtractCallback {
     public:
         BufferExtractCallback( const BitInputArchive& inputArchive,
-                               std::map< tstring, std::vector< byte_t > >& buffersMap );
+                               std::map< tstring, buffer_t >& buffersMap );
 
         BufferExtractCallback( const BufferExtractCallback& ) = delete;
 
@@ -35,7 +36,7 @@ class BufferExtractCallback final : public ExtractCallback {
         ~BufferExtractCallback() override = default;
 
     private:
-        std::map< tstring, std::vector< byte_t > >& mBuffersMap;
+        std::map< tstring, buffer_t >& mBuffersMap;
         CMyComPtr< ISequentialOutStream > mOutMemStream;
 
         void releaseStream() override;
diff --git a/src/internal/bufferitem.cpp b/src/internal/bufferitem.cpp
index 7b036252..448afc79 100644
--- a/src/internal/bufferitem.cpp
+++ b/src/internal/bufferitem.cpp
@@ -21,11 +21,10 @@
 
 #include <cstdint>
 #include <utility>
-#include <vector>
 
 namespace bit7z {
 
-BufferItem::BufferItem( const std::vector< byte_t >& buffer, fs::path name )
+BufferItem::BufferItem( const buffer_t& buffer, fs::path name )
     : mBuffer{ buffer }, mBufferName{ std::move( name ) } {}
 
 auto BufferItem::name() const -> tstring {
diff --git a/src/internal/bufferitem.hpp b/src/internal/bufferitem.hpp
index 52ec4d3e..2e2dd634 100644
--- a/src/internal/bufferitem.hpp
+++ b/src/internal/bufferitem.hpp
@@ -18,7 +18,7 @@ namespace bit7z {
 
 class BufferItem final : public GenericInputItem {
     public:
-        explicit BufferItem( const std::vector< byte_t >& buffer, fs::path name );
+        explicit BufferItem( const buffer_t& buffer, fs::path name );
 
         BIT7Z_NODISCARD auto name() const -> tstring override;
 
@@ -41,7 +41,7 @@ class BufferItem final : public GenericInputItem {
         BIT7Z_NODISCARD auto attributes() const noexcept -> uint32_t override;
 
     private:
-        const std::vector< byte_t >& mBuffer;
+        const buffer_t& mBuffer;
         fs::path mBufferName;
 };
 
diff --git a/src/internal/callback.hpp b/src/internal/callback.hpp
index 85e7cbf1..3fc2f0ac 100644
--- a/src/internal/callback.hpp
+++ b/src/internal/callback.hpp
@@ -10,7 +10,6 @@
 #ifndef CALLBACK_HPP
 #define CALLBACK_HPP
 
-#include "bitabstractarchivehandler.hpp"
 #include "internal/com.hpp"
 #include "internal/guids.hpp"
 
@@ -28,6 +27,8 @@ namespace bit7z {
 #   define CALLBACK_DESTRUCTOR( x ) virtual x
 #endif
 
+class BitAbstractArchiveHandler;
+
 class Callback : protected CMyUnknownImp {
     public:
         Callback( const Callback& ) = delete;
diff --git a/src/internal/cbufferinstream.cpp b/src/internal/cbufferinstream.cpp
index f0763e35..1efdd79c 100644
--- a/src/internal/cbufferinstream.cpp
+++ b/src/internal/cbufferinstream.cpp
@@ -26,7 +26,7 @@
 
 namespace bit7z {
 
-CBufferInStream::CBufferInStream( const std::vector< byte_t >& inBuffer )
+CBufferInStream::CBufferInStream( const buffer_t& inBuffer )
     : mBuffer( inBuffer ), mCurrentPosition{ mBuffer.begin() } {}
 
 COM_DECLSPEC_NOTHROW
diff --git a/src/internal/cbufferinstream.hpp b/src/internal/cbufferinstream.hpp
index 0ad2ec64..8669e235 100644
--- a/src/internal/cbufferinstream.hpp
+++ b/src/internal/cbufferinstream.hpp
@@ -17,13 +17,11 @@
 
 #include <7zip/IStream.h>
 
-#include <vector>
-
 namespace bit7z {
 
 class CBufferInStream final : public IInStream, public CMyUnknownImp {
     public:
-        explicit CBufferInStream( const std::vector< byte_t >& inBuffer );
+        explicit CBufferInStream( const buffer_t& inBuffer );
 
         CBufferInStream( const CBufferInStream& ) = delete;
 
diff --git a/src/internal/cbufferoutstream.cpp b/src/internal/cbufferoutstream.cpp
index 17a44cfd..4181c86e 100644
--- a/src/internal/cbufferoutstream.cpp
+++ b/src/internal/cbufferoutstream.cpp
@@ -21,13 +21,13 @@
 
 namespace bit7z {
 
-CBufferOutStream::CBufferOutStream( std::vector< byte_t >& outBuffer )
+CBufferOutStream::CBufferOutStream( buffer_t& outBuffer )
     : mBuffer( outBuffer ), mCurrentPosition{ mBuffer.begin() } {}
 
 COM_DECLSPEC_NOTHROW
 STDMETHODIMP CBufferOutStream::SetSize( UInt64 newSize ) noexcept {
     try {
-        mBuffer.resize( static_cast< std::vector< byte_t >::size_type >( newSize ) );
+        mBuffer.resize( static_cast< buffer_t::size_type >( newSize ) );
         return S_OK;
     } catch ( ... ) {
         return E_OUTOFMEMORY;
diff --git a/src/internal/cbufferoutstream.hpp b/src/internal/cbufferoutstream.hpp
index ad6705b3..b2b1282d 100644
--- a/src/internal/cbufferoutstream.hpp
+++ b/src/internal/cbufferoutstream.hpp
@@ -21,7 +21,7 @@ namespace bit7z {
 
 class CBufferOutStream final : public IOutStream, public CMyUnknownImp {
     public:
-        explicit CBufferOutStream( std::vector< byte_t >& outBuffer );
+        explicit CBufferOutStream( buffer_t& outBuffer );
 
         CBufferOutStream( const CBufferOutStream& ) = delete;
 
diff --git a/src/internal/cmultivolumeoutstream.hpp b/src/internal/cmultivolumeoutstream.hpp
index f2a44447..1a644d9e 100644
--- a/src/internal/cmultivolumeoutstream.hpp
+++ b/src/internal/cmultivolumeoutstream.hpp
@@ -17,7 +17,6 @@
 #include <7zip/IStream.h>
 
 #include <cstdint>
-#include <string>
 #include <vector>
 
 namespace bit7z {
diff --git a/src/internal/dateutil.hpp b/src/internal/dateutil.hpp
index 43cd2edf..37724b26 100644
--- a/src/internal/dateutil.hpp
+++ b/src/internal/dateutil.hpp
@@ -14,8 +14,9 @@
 #include "bitwindows.hpp"
 #include "internal/fs.hpp"
 
-#include <chrono>
+#ifndef _WIN32
 #include <ctime>
+#endif
 
 namespace bit7z {
 
diff --git a/src/internal/extractcallback.cpp b/src/internal/extractcallback.cpp
index c1c31c12..a1644d59 100644
--- a/src/internal/extractcallback.cpp
+++ b/src/internal/extractcallback.cpp
@@ -12,7 +12,9 @@
 
 #include "internal/extractcallback.hpp"
 
+#include "bitabstractarchivehandler.hpp"
 #include "bitexception.hpp"
+#include "bitinputarchive.hpp"
 #include "internal/operationcategory.hpp"
 #include "internal/stringutil.hpp"
 
@@ -140,4 +142,24 @@ STDMETHODIMP ExtractCallback::CryptoGetTextPassword( BSTR* password ) noexcept {
     return StringToBstr( pass.c_str(), password );
 }
 
+auto ExtractCallback::isItemFolder( uint32_t index ) const -> bool {
+    return mInputArchive.isItemFolder( index );
+}
+
+auto ExtractCallback::itemProperty( uint32_t index, BitProperty property ) const -> BitPropVariant {
+    return mInputArchive.itemProperty( index, property );
+}
+
+auto ExtractCallback::inputArchive() const -> const BitInputArchive& {
+    return mInputArchive;
+}
+
+auto ExtractCallback::errorException() const -> const std::exception_ptr& {
+    return mErrorException;
+}
+
+auto ExtractCallback::extractMode() const -> ExtractMode {
+    return mExtractMode;
+}
+
 } // namespace bit7z
diff --git a/src/internal/extractcallback.hpp b/src/internal/extractcallback.hpp
index f6086c91..8f41d88f 100644
--- a/src/internal/extractcallback.hpp
+++ b/src/internal/extractcallback.hpp
@@ -10,7 +10,7 @@
 #ifndef EXTRACTCALLBACK_HPP
 #define EXTRACTCALLBACK_HPP
 
-#include "bitinputarchive.hpp"
+#include "bitpropvariant.hpp"
 #include "internal/callback.hpp"
 #include "internal/macros.hpp"
 #include "internal/operationresult.hpp"
@@ -25,6 +25,8 @@ using namespace NArchive::NExtract;
 
 namespace bit7z {
 
+class BitInputArchive;
+
 constexpr auto kEmptyFileAlias = BIT7Z_STRING( "[Content]" );
 
 enum struct ExtractMode {
@@ -68,9 +70,7 @@ class ExtractCallback : public Callback,
         BIT7Z_STDMETHOD( SetOperationResult, Int32 operationResult );
 
         BIT7Z_NODISCARD
-        inline auto errorException() const -> const std::exception_ptr& {
-            return mErrorException;
-        }
+        auto errorException() const -> const std::exception_ptr&;
 
         // NOLINTNEXTLINE(modernize-use-noexcept, modernize-use-trailing-return-type, readability-identifier-length)
         MY_UNKNOWN_IMP3( IArchiveExtractCallback, ICompressProgressInfo, ICryptoGetTextPassword ) //-V2507 //-V2511 //-V835
@@ -79,24 +79,16 @@ class ExtractCallback : public Callback,
         explicit ExtractCallback( const BitInputArchive& inputArchive );
 
         BIT7Z_NODISCARD
-        inline auto extractMode() const -> ExtractMode {
-            return mExtractMode;
-        }
+        auto extractMode() const -> ExtractMode;
 
         BIT7Z_NODISCARD
-        inline auto isItemFolder( uint32_t index ) const -> bool {
-            return mInputArchive.isItemFolder( index );
-        }
+        auto isItemFolder( uint32_t index ) const -> bool;
 
         BIT7Z_NODISCARD
-        inline auto itemProperty( uint32_t index, BitProperty property ) const -> BitPropVariant {
-            return mInputArchive.itemProperty( index, property );
-        }
+        auto itemProperty( uint32_t index, BitProperty property ) const -> BitPropVariant;
 
         BIT7Z_NODISCARD
-        inline auto inputArchive() const -> const BitInputArchive& {
-            return mInputArchive;
-        }
+        auto inputArchive() const -> const BitInputArchive&;
 
         virtual auto finishOperation( OperationResult operationResult ) -> HRESULT;
 
diff --git a/src/internal/fileextractcallback.cpp b/src/internal/fileextractcallback.cpp
index 063320f3..1095e7be 100644
--- a/src/internal/fileextractcallback.cpp
+++ b/src/internal/fileextractcallback.cpp
@@ -13,6 +13,7 @@
 #include "internal/fileextractcallback.hpp"
 
 #include "bitexception.hpp"
+#include "bitinputarchive.hpp"
 #include "internal/fsutil.hpp"
 #include "internal/stringutil.hpp"
 #include "internal/util.hpp"
diff --git a/src/internal/fileextractcallback.hpp b/src/internal/fileextractcallback.hpp
index 6226e15f..d5c989d2 100644
--- a/src/internal/fileextractcallback.hpp
+++ b/src/internal/fileextractcallback.hpp
@@ -16,6 +16,8 @@
 
 namespace bit7z {
 
+class BitInputArchive;
+
 class FileExtractCallback final : public ExtractCallback {
     public:
         FileExtractCallback( const BitInputArchive& inputArchive, const tstring& directoryPath );
diff --git a/src/internal/fixedbufferextractcallback.cpp b/src/internal/fixedbufferextractcallback.cpp
index d97b8011..07a2f5f9 100644
--- a/src/internal/fixedbufferextractcallback.cpp
+++ b/src/internal/fixedbufferextractcallback.cpp
@@ -12,6 +12,7 @@
 
 #include "internal/fixedbufferextractcallback.hpp"
 
+#include "bitabstractarchivehandler.hpp"
 #include "internal/cfixedbufferoutstream.hpp"
 #include "internal/util.hpp"
 
diff --git a/src/internal/fixedbufferextractcallback.hpp b/src/internal/fixedbufferextractcallback.hpp
index e6c26d21..04e26114 100644
--- a/src/internal/fixedbufferextractcallback.hpp
+++ b/src/internal/fixedbufferextractcallback.hpp
@@ -15,6 +15,8 @@
 
 namespace bit7z {
 
+class BitInputArchive;
+
 class FixedBufferExtractCallback final : public ExtractCallback {
     public:
         FixedBufferExtractCallback( const BitInputArchive& inputArchive, byte_t* buffer, size_t size );
diff --git a/src/internal/formatdetect.cpp b/src/internal/formatdetect.cpp
index 8b5944d7..5ab750c7 100644
--- a/src/internal/formatdetect.cpp
+++ b/src/internal/formatdetect.cpp
@@ -18,6 +18,7 @@
 
 #include "biterror.hpp"
 #include "bitexception.hpp"
+#include "bitformat.hpp"
 #include "internal/fsutil.hpp"
 #ifndef _WIN32
 #include "internal/guiddef.hpp"
diff --git a/src/internal/formatdetect.hpp b/src/internal/formatdetect.hpp
index e0774f0a..67c497c6 100644
--- a/src/internal/formatdetect.hpp
+++ b/src/internal/formatdetect.hpp
@@ -14,13 +14,14 @@
 
 #ifdef BIT7Z_AUTO_FORMAT
 
-#include "bitformat.hpp"
 #include "bitfs.hpp"
 
 struct IInStream;
 
 namespace bit7z {
 
+class BitInFormat;
+
 auto detect_format_from_extension( const fs::path& inFile ) -> const BitInFormat&;
 
 auto detect_format_from_signature( IInStream * stream ) -> const BitInFormat&;
diff --git a/src/internal/hresultcategory.cpp b/src/internal/hresultcategory.cpp
index 064660c8..f26eed7c 100644
--- a/src/internal/hresultcategory.cpp
+++ b/src/internal/hresultcategory.cpp
@@ -22,7 +22,7 @@ auto HRESULTCategory::name() const noexcept -> const char* {
 
 auto HRESULTCategory::message( int errorValue ) const -> std::string {
 #ifdef _WIN32
-    // Note: also MinGW supports FormatMessageA!
+    // Note: also MinGW supports FormatMessageA, so we use it.
     LPSTR messageBuffer = nullptr;
     auto msgSize = FormatMessageA( FORMAT_MESSAGE_ALLOCATE_BUFFER |
                                    FORMAT_MESSAGE_FROM_SYSTEM |
diff --git a/src/internal/opencallback.cpp b/src/internal/opencallback.cpp
index 57b4684c..94cff104 100644
--- a/src/internal/opencallback.cpp
+++ b/src/internal/opencallback.cpp
@@ -12,6 +12,7 @@
 
 #include "internal/opencallback.hpp"
 
+#include "bitabstractarchivehandler.hpp"
 #include "bitexception.hpp"
 #include "internal/cfileinstream.hpp"
 #include "internal/stringutil.hpp"
diff --git a/src/internal/opencallback.hpp b/src/internal/opencallback.hpp
index 824c2d60..baffd6f3 100644
--- a/src/internal/opencallback.hpp
+++ b/src/internal/opencallback.hpp
@@ -10,7 +10,6 @@
 #ifndef OPENCALLBACK_HPP
 #define OPENCALLBACK_HPP
 
-#include "bitabstractarchivehandler.hpp"
 #include "internal/callback.hpp"
 #include "internal/com.hpp"
 #include "internal/fsitem.hpp"
@@ -23,6 +22,8 @@ namespace bit7z {
 
 using filesystem::FilesystemItem;
 
+class BitAbstractArchiveHandler;
+
 class OpenCallback final : public IArchiveOpenCallback,
                            public IArchiveOpenVolumeCallback,
                            public IArchiveOpenSetSubArchiveName,
diff --git a/src/internal/processeditem.cpp b/src/internal/processeditem.cpp
index 621cb448..272a15b0 100644
--- a/src/internal/processeditem.cpp
+++ b/src/internal/processeditem.cpp
@@ -13,6 +13,8 @@
 #include "internal/processeditem.hpp"
 
 #include "bitexception.hpp"
+#include "bitinputarchive.hpp"
+#include "bitpropvariant.hpp"
 
 namespace bit7z {
 
diff --git a/src/internal/processeditem.hpp b/src/internal/processeditem.hpp
index e87d92b8..57e7b89a 100644
--- a/src/internal/processeditem.hpp
+++ b/src/internal/processeditem.hpp
@@ -10,12 +10,13 @@
 #ifndef PROCESSEDITEM_HPP
 #define PROCESSEDITEM_HPP
 
-#include "bitinputarchive.hpp"
 #include "internal/fs.hpp"
 #include "internal/windows.hpp"
 
 namespace bit7z {
 
+class BitInputArchive;
+
 class ProcessedItem final {
     public:
         ProcessedItem();
diff --git a/src/internal/renameditem.cpp b/src/internal/renameditem.cpp
index df43e123..fedd6535 100644
--- a/src/internal/renameditem.cpp
+++ b/src/internal/renameditem.cpp
@@ -12,6 +12,7 @@
 
 #include "internal/renameditem.hpp"
 
+#include "bitinputarchive.hpp"
 #include "internal/dateutil.hpp"
 #include "internal/fsutil.hpp"
 #include "internal/stringutil.hpp"
diff --git a/src/internal/renameditem.hpp b/src/internal/renameditem.hpp
index ad729932..939f1bf2 100644
--- a/src/internal/renameditem.hpp
+++ b/src/internal/renameditem.hpp
@@ -10,11 +10,12 @@
 #ifndef RENAMEDITEM_HPP
 #define RENAMEDITEM_HPP
 
-#include "bitinputarchive.hpp"
 #include "internal/genericinputitem.hpp"
 
 namespace bit7z {
 
+class BitInputArchive;
+
 class RenamedItem final : public GenericInputItem {
     public:
         explicit RenamedItem( const BitInputArchive& inputArchive, uint32_t index, const tstring& newPath );
diff --git a/src/internal/streamextractcallback.cpp b/src/internal/streamextractcallback.cpp
index 9c8b1f85..aa9bdbba 100644
--- a/src/internal/streamextractcallback.cpp
+++ b/src/internal/streamextractcallback.cpp
@@ -12,6 +12,7 @@
 
 #include "internal/streamextractcallback.hpp"
 
+#include "bitinputarchive.hpp"
 #include "internal/cstdoutstream.hpp"
 #include "internal/util.hpp"
 
diff --git a/src/internal/streamextractcallback.hpp b/src/internal/streamextractcallback.hpp
index 374ec992..e3a40de0 100644
--- a/src/internal/streamextractcallback.hpp
+++ b/src/internal/streamextractcallback.hpp
@@ -16,6 +16,8 @@
 
 namespace bit7z {
 
+class BitInputArchive;
+
 class StreamExtractCallback final : public ExtractCallback {
     public:
         StreamExtractCallback( const BitInputArchive& inputArchive, std::ostream& outputStream );
diff --git a/src/internal/updatecallback.hpp b/src/internal/updatecallback.hpp
index 1b0a753e..f60b0a9a 100644
--- a/src/internal/updatecallback.hpp
+++ b/src/internal/updatecallback.hpp
@@ -10,7 +10,6 @@
 #ifndef UPDATECALLBACK_HPP
 #define UPDATECALLBACK_HPP
 
-#include "bitoutputarchive.hpp"
 #include "internal/callback.hpp"
 #include "internal/macros.hpp"
 
@@ -20,6 +19,8 @@
 
 namespace bit7z {
 
+class BitOutputArchive;
+
 class UpdateCallback final : public Callback,
                              public IArchiveUpdateCallback2,
                              public ICompressProgressInfo,
diff --git a/tests/src/utils/filesystem.hpp b/tests/src/utils/filesystem.hpp
index 0856aa89..74aa03e4 100644
--- a/tests/src/utils/filesystem.hpp
+++ b/tests/src/utils/filesystem.hpp
@@ -62,14 +62,14 @@ inline auto set_current_dir( const fs::path& dir ) -> bool {
     return !error;
 }
 
-inline auto load_file( fs::path const& inFile ) -> std::vector< bit7z::byte_t > {
+inline auto load_file( fs::path const& inFile ) -> buffer_t {
     fs::ifstream ifs{ inFile, fs::ifstream::binary };
     if ( !ifs.is_open() ) {
         return {};
     }
     noskipws( ifs ); //no skip spaces!
     auto size = fs::file_size( inFile );
-    std::vector< bit7z::byte_t > result( size );
+    buffer_t result( size );
     // NOLINTNEXTLINE(*-pro-type-reinterpret-cast)
     ifs.read( reinterpret_cast<char*>( result.data() ), result.cend() - result.cbegin() );
     //note: using basic_ifstream with istreambuf_iterator<std::byte> would be cleaner, but it is 10x slower.