anchor.diff:  
     postPatch = ''
       substituteInPlace GNUmakefile \
  -      --replace "AR = libtool" "AR = ar" \
  +      --replace "AR = /usr/bin/libtool" "AR = ar" \
         --replace "ARFLAGS = -static -o" "ARFLAGS = -cru"
     '';
   
  +  buildInputs = lib.optionals (stdenv.cc.isClang && withOpenMP) [ llvmPackages.openmp ];
  +
     makeFlags = [ "PREFIX=${placeholder "out"}" ];
  +
     buildFlags =
          lib.optional enableStatic "static"
       ++ lib.optional enableShared "shared"
       ++ [ "libcryptopp.pc" ];
  +
     enableParallelBuilding = true;
     hardeningDisable = [ "fortify" ];
  +  CXXFLAGS = lib.optionals (withOpenMP) [ "-fopenmp" ];
   
     doCheck = true;
   
  
positive.code: 
    installTargets = [ "install-lib" ];
    installFlags = [ "LDCONF=true" ];
    postInstall = lib.optionalString (!stdenv.hostPlatform.isDarwin) ''
      ln -sr $out/lib/libcryptopp.so.${version} $out/lib/libcryptopp.so.${lib.versions.majorMinor version}
      ln -sr $out/lib/libcryptopp.so.${version} $out/lib/libcryptopp.so.${lib.versions.major version}
    '';
  
    meta = {
      description = "Crypto++, a free C++ class library of cryptographic schemes";
      homepage = "https://cryptopp.com/";
      changelog = "https://raw.githubusercontent.com/weidai11/cryptopp/CRYPTOPP_${underscoredVersion}/History.txt";
      license = with lib.licenses; [ boost publicDomain ];
      platforms = lib.platforms.all;
      maintainers = with lib.maintainers; [ c0bw3b ];
    };
  }
  
negative.code: { lib
  , stdenv
  , fetchFromGitHub
  , enableStatic ? stdenv.hostPlatform.isStatic
  , enableShared ? !enableStatic
  # Multi-threading with OpenMP is disabled by default
  # more info on https://www.cryptopp.com/wiki/OpenMP
  , withOpenMP ? false
  , llvmPackages
  }:
  
  stdenv.mkDerivation rec {
  