C++ “no match for operator=“ error in lambda function

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• How to patch IAT to hook Windows Native API like LdrGetProcedureAddress?

  I am completely new to IAT hooking. Goal is to provide extra functionality by wrapping Windows API.

  I write my wrappers in a dll and use (IAT patcher). This tool lists all the imported API from IAT of a binary; I can select any function and define replacement function (One of the function from my wrapper dll) and it works by patching the IAT in some way.

  (Pardon me for not explaining how IAT patcher internally works, as I don't know right now)

  But Windows native API (e.g. NtOpenFile, LdrGetProcedureAddress) is not explicitly imported and does not have any entry in IAT, so IAT patcher isn't helping.

  I also know that there are ways to hook APIs at execution time by injecting dlls (used by rootkits), but I am really hoping that I could hook Windows Naive API by modifying PE binary itself before executing it.
• "No match for operator" when including QtSql library in QT

  Upon writing include for the QtSql library into the code, any attempt at compilation returns "no match for operator". Deleting/commenting out the line with "include" gets rid of the errors.

  The exact errors that occur are:

  no match for 'operator==' (operand types are 'std::thread::native_handle_type{aka ptw32_handle_t}' and 'std::thread::native_handle_type{aka ptw32_handle_t}')
  no match for 'operator<' (operand types are 'std::thread::native_handle_type{aka ptw32_handle_t}' and 'std::thread::native_handle_type{aka ptw32_handle_t}')
  

  The files in my project:

  Upload.pro

  QT += core
  QT -= gui
  QT += sql
  
  CONFIG += c++11
  
  TARGET = Upload
  CONFIG -= app_bundle
  
  TEMPLATE = app
  
  SOURCES += main.cpp
  
  unix|win32: LIBS += -L'C:/Program Files/PostgreSQL/9.5/lib/' -llibpq
  
  INCLUDEPATH += 'C:/Program Files/PostgreSQL/9.5/include'
  DEPENDPATH += 'C:/Program Files/PostgreSQL/9.5/include'
  

  main.cpp

  #include <QCoreApplication>
  
  #include <QFile>
  #include <QDebug>
  #include <QTextStream>
  #include <QtSql>
  #include <QSqlQuery>
  
  using namespace std;
  
  int main(int argc, char *argv[])
  {
      QCoreApplication a(argc, argv);
  
      return 0;
  }
  

  I am using QT 5.12.0 with QT Creator 4.8.0 (MinGW 7.3.0 64 bit is set as compiler).

  The program was installed with an offline installer, so it's not custom-built, which is why I'm hesitant to consider it a bug in program itself. Searching for similar issues also didn't give me any results.

  I have previously solved similar sql-related programming problems using an earlier version of QT on a 32-bit computer, so I'm almost sure the code is fine as well.

  Is this an issue with compiler settings? Or is that some complication in a newer version of QT?
• Why does MSVC++ require std::setprecision to enable full precision output with std::hexfloat?

  As far as I'm aware, the following line is all that is required to output doubles in hex to full precision:

  std::cout << std::hexfloat << yourDouble << std::endl;
  

  But using MSVC++ in Visual Studio 17 this only prints a double to 6 hex-digits. See my code (truncated for clarity):

  std::ifstream cacheF(pToFile, std::ios::in);
  if (!cacheF.is_open()) {
      std::cerr << "Could not open " << pToFile << "!" << std::endl;
      return 1;
  }
  
  bool readSuccess = true;
  unsigned long long sumBegin, cached[2];
  double previousTime;
  readSuccess = readSuccess && (cacheF >> std::dec >> sumBegin);
  readSuccess = readSuccess && (cacheF >> std::hexfloat >> previousTime);
  for (int i = 0; i < 2; i++) readSuccess = readSuccess && (cacheF >> std::hex >> cached[i]);
  
  cacheF.close();
  
  if (!readSuccess) {
      std::cerr << "Cache reload failed due to improper file formatting!" << std::endl;
  }
  
  std::cout << std::hexfloat << previousTime << std::endl;
  std::cout << std::setprecision(13) << std::hexfloat << previousTime << std::endl;
  

  Input file looks like this:

  1045644800006
  0x1.567be0370cdc8p+7
  C6CCFEDA2563B0D1
  5E3492440B4BE8B2
  

  Output is:

  0x1.567be0p+7
  0x1.567be0370cdc8p+7
  

  It's been a while since I last tried this with GCC but if I remember correctly it produced full double precision output without needing setprecision. Can anyone confirm if this is an MSVC++ specific behavior, and if it is why?
• Searching keyword in objects

  I have a list of objects each with a first name and last name. Im trying to make a keyword search function for both their names, so my logic is if i concatenate their first and last names, then check if the sum of both names contains the keyword, return the object as a string. I'm trying to write it as a lambda expression but I'm just not getting it. The function returns nothing every time. Im completely new to lambdas so the this simple task is quite difficult for me. When i read my code below.. i see this: Each element concatenate their names, then filter by seeing if the string contains the keyword, then convert the stream to a list objects, then convert objects to a string, then return the string. Thanks to anyone who can help.

  public String generateUserByKeyword2(String keyword){
   return  users.stream()
           .map(x-> x.getFirstName() + x.getLastName().toLowerCase())
           .filter(x -> x.contains(keyword.toLowerCase()))
           .collect(Collectors.toList())
           .toString();
  }  
  
• Get first non null object, non empty string field value from a list

  I have a

  List<ClassA> listOfClassA;
  

  ClassA contains another object let say insideObj. I want to fetch the first instance of insideObj which is non null, and contains a non empty field which is a string. Currently i am doing

  for (ClassA objA : listOfClassA) {
          if(objA.getInsideObj() != null && !objA.getInsideObj().getName().isEmpty())
              return objA.getInsideObj().getName();
      }
  

  Is there a cleaner way to do this in Java 8?
• Where's the power of functional interfaces in Java?

  I am reading about functional programming basics. Anyway, I make some examples trying to understand the concept and use it correctly.

  I do not get the power of this functional programming. Is it only in writing lambdas instead of normal code?

  If we have this class:

  public class Dinosaurio {
      private boolean esMamifero;
      private String nombre;
      public Dinosaurio(String n, boolean esMam) {...}
  //getters and setters
  

  This functional interface:

  @FunctionalInterface
  public interface DinosaurioTester {
      boolean test(Dinosaurio d);
  }
  

  And this main class:

  public class LambdaMain {
  
      public static void main(String[] args) {
  
          List<Dinosaurio> lista = new ArrayList<>(); 
          lista.add(new Dinosaurio("Manolo", true));
          lista.add(new Dinosaurio("Pepe", true));
          lista.add(new Dinosaurio("Paco", false));
          lista.add(new Dinosaurio("Curro", true));
          lista.add(new Dinosaurio("Nemo", false));
  
          pintadorDinosaurios(lista, a->a.isEsMamifero());
      }
  
      public static void pintadorDinosaurios(List<Dinosaurio> ld, DinosaurioTester dt) {
  
          for(Dinosaurio d : ld) {
              if(dt.test(d)) {
                  System.out.println(d.getNombre());
              }
          }
  
      }
  
  }
  

  This works great, but I don't see a real advantage from using this:

  if(dt.test(d)) {
  

  instead of this:

  if(d.isEsMamifero())
  

  Edit: Sure this example is an bad example code for functional programming real usage. But it's all that I can think about it now.
• String to boolean java

  public class Boolean
  {
      public static void main (String[] args)
      {
          boolean bool = Boolean.parseBoolean(args[0]);
          if (bool == true)
          {
              System.out.println("Your choice: true");
          }
          else
          {
              System.out.println("Your choice: false");
          }
      }
  }
  

  My question is if I can start my program with input "true" or "false" and get this value as boolean variable? Now I have this error:

  cannot find symbol (parseBoolean)
• Macros for packing and unpacking 3-D arrays in Verilog

  I am a beginner with Verilog, I want to pack and unpack 3-D inputs and outputs in the code for which I have defined two macros as below:

  `define PACK_3D(PK_WIDTH,PK_HEIGHT, PK_DEPTH, PK_SRC, PK_DEST) \
  genvar pk_idh; \
  genvar pk_idd; \
  generate for (pk_idd=0; pk_idd<(PK_DEPTH); pk_idd=pk_idd+1) begin \
    generate for (pk_idh=0; pk_idh<(PK_HEIGHT); pk_idh=pk_idh+1) begin \
        assign PK_DEST[pk_idd*(PK_HEIGHT*PK_WIDTH) + pk_idh*(PK_WIDTH) + (PK_WIDTH-1): pk_idd*(PK_HEIGHT*PK_WIDTH) + pk_idh*(PK_WIDTH)] = PK_SRC[pk_idd][pk_idh][(PK_WIDTH)-1):0]; \
    end \
  endgenerate \
  end \
  endgenerate
  
  
  
  `define UNPACK_3D(PK_WIDTH, PK_HEIGHT, PK_DEPTH, PK_SRC, PK_DEST) \
  genvar pk_idh; \
  genvar pk_idd; \
  generate for (pk_idd=0; pk_idd<(PK_DEPTH); pk_idd=pk_idd+1) begin \
    generate for (pk_idh=0; pk_idh<(PK_HEIGHT); pk_idh=pk_idh+1) begin \
      assign PK_DEST[pk_idd][pk_idh][(PK_WIDTH)-1):0] = PK_SRC[pk_idd*(PK_HEIGHT*PK_WIDTH) + pk_idh*(PK_WIDTH) + (PK_WIDTH-1): pk_idd*(PK_HEIGHT*PK_WIDTH) + pk_idh*(PK_WIDTH)]; \
    end \
    endgenerate \
  end \
  endgenerate
  

  Next, I have built an add module to add two 3-D matrices and return the output as below:

  module add(clk, rst, g_input, e_input, o);
  input clk,rst;   
  localparam num=4;  
  localparam h = 3;
  localparam w = 3;
  localparam d = 2;
  
  input [2*num*h*w*d-1:0] g_input; 
  input [2*num*h*w*d-1:0] e_input;  
  output reg [2*num*h*w*d-1:0] o;
  
  reg [2*num -1: 0] g_unpack[d-1:0][h-1:0][w-1:0];
  reg [2*num -1: 0] e_unpack[d-1:0][h-1:0][w-1:0];
  reg [2*num -1: 0] o_unpack[d-1:0][h-1:0][w-1:0];
  
  
  `UNPACK_3D(w,h,d,g_input,g_unpack);
  `UNPACK_3D(w,h,d,e_input,e_unpack);
  
  integer i_d, i_h, i_w 
  
  always@*   // always combinational block
    begin
      for (i_d = 0; i_d < d; i_d = i_d+1)
        begin
        for (i_h = 0; i_h < d; i_h = i_h+1)
          begin
          for (i_w = 0; i_w < d; i_w = i_w+1)
            begin
              o_unpack[i_d][i_h][i_w] = g_unpack[i_d][i_h][i_w] + e_unpack[i_d][i_h][i_w];
            end
          end
        end
    end
  
  `PACK_3D(w,h,d,o_unpack,o);
  endmodule
  

  I got the idea from the this discussion. Although I when I try to compile the code above, I get a compilation error:

  Error:  ./add.v:43: Syntax error at or near token 'generate'
      in macro "UNPACK_3D"
      called from file "./add.v" (line 43). (VER-294)
  Error:  ./add.v:43: Syntax error at or near token '('
      in macro "UNPACK_3D"
      called from file "./add.v" (line 43). (VER-294)
  Error:  ./add.v:44: Syntax error at or near token 'generate'
      in macro "UNPACK_3D"
      called from file "./add.v" (line 44). (VER-294)
  Error:  ./add.v:44: Syntax error at or near token '('
      in macro "UNPACK_3D"
      called from file "./add.v" (line 44). (VER-294)
  Error:  ./add.v:44: Syntax error at or near token '('
      in macro "UNPACK_3D"
      called from file "./add.v" (line 44). (VER-294)
  Error:  ./add.v:48: Syntax error at or near token 'always'. (VER-294)
  Error:  ./add.v:50: Syntax error at or near token ';'. (VER-294)
  Error:  ./add.v:52: Syntax error at or near token ';'. (VER-294)
  Error:  ./add.v:54: Syntax error at or near token ';'. (VER-294)
  Error:  ./add.v:62: Syntax error at or near token 'generate'
      in macro "PACK_3D"
      called from file "./add.v" (line 62). (VER-294)
  Error:  ./add.v:62: Syntax error at or near token '('
      in macro "PACK_3D"
      called from file "./add.v" (line 62). (VER-294)
  Error:  ./add.v:62: Syntax error at or near token '('
      in macro "PACK_3D"
      called from file "./add.v" (line 62). (VER-294)
  *** Presto compilation terminated with 12 errors. ***
  

  Can anyone please help to resolve this? Thank you.
• -bash: gcc-8.0.2: command not found (But it's there)

  My mac cann't find the gcc.

  DorothydeMacBook:Desktop dorothy$ gcc
      -bash: gcc-8.0.2: command not found
  

  But it exits.

  DorothydeMacBook:Desktop dorothy$ which gcc
  /usr/local/bin/gcc
  

  I can find them in /usr/local/bin

  x86_64-apple-darwin18.2.0-c++-8
  x86_64-apple-darwin18.2.0-g++-8
  x86_64-apple-darwin18.2.0-gcc-8
  x86_64-apple-darwin18.2.0-gcc-8.2.0
  x86_64-apple-darwin18.2.0-gcc-ar-8
  x86_64-apple-darwin18.2.0-gcc-nm-8
  x86_64-apple-darwin18.2.0-gcc-ranlib-8
  x86_64-apple-darwin18.2.0-gfortran-8
  g++                 
  g++-8               
  gcc                 
  gcc-8                   
  gcc-ar              
  gcc-ar-8                
  gcc-nm                  
  gcc-nm-8                
  gcc-ranlib      
  gcc-ranlib-8
  
     DorothydeMacBook:~ dorothy$ env
  TERM_PROGRAM=Apple_Terminal
  TERM=xterm-256color
  SHELL=/bin/bash
  TMPDIR=/var/folders/dg/l7bh29111hl_7jsfspzbs2d80000gn/T/
  Apple_PubSub_Socket_Render=/private/tmp/com.apple.launchd.92LjvvFjN3/Render
  TERM_PROGRAM_VERSION=421.1
  OLDPWD=/Users/dorothy/Desktop
  TERM_SESSION_ID=83E312BB-F4C2-4DA7-B123-38BAA4242C89
  USER=dorothy
  SSH_AUTH_SOCK=/private/tmp/com.apple.launchd.Y7k1UOMg8c/Listeners
  PATH=/Library/Frameworks/Python.framework/Versions/3.6/bin:/usr/local/Cellar/gcc/8.0.2/lib:/usr/local/Cellar/gcc/8.0.2/bin:/Library/Frameworks/Python.framework/Versions/3.6/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Library/TeX/texbin:/usr/local/share/dotnet:/opt/X11/bin:/Library/Frameworks/Mono.framework/Versions/Current/Commands:/Applications/Xamarin Workbooks.app/Contents/SharedSupport/path-bin
  PWD=/Users/dorothyXPC_FLAGS=0x0
  XPC_SERVICE_NAME=0
  HOME=/Users/dorothy
  SHLVL=1
  LOGNAME=dorothy
  LC_CTYPE=UTF-8
  DISPLAY=/private/tmp/com.apple.launchd.U7xfsLeEtc/org.macosforge.xquartz:0
  MyComputer=u1795058@joshua.dcs.warwick.ac.uk
  SECURITYSESSIONID=186a8
  _=/usr/bin/env
  

  The details of the system path are listed:

   The /etc/profile
  
  # System-wide .profile for sh(1)
  
  if [ -x /usr/libexec/path_helper ]; then
          eval `/usr/libexec/path_helper -s`
  fi
  
  if [ "${BASH-no}" != "no" ]; then
          [ -r /etc/bashrc ] && . /etc/bashrc
  fi
  ~                                                                               
  ~                                                                               
  

  How can I use gcc ?